TY - THES
A1 - Lekszas, Caroline
T1 - Erweiterung des genetischen Mutationsspektrums verschiedener Krankheitsbilder und Identifizierung neuer krankheitsrelevanter Gene im Menschen mittels Whole Exome Sequenzierung
T1 - Expansion of the genetic mutation spectrum of different pathologies and identification of new disease-relevant genes in humans by means of Whole Exome Sequencing
N2 - Trotz der rasanten Entwicklung molekulargenetischer Analysemethoden sind die Auslöser vieler Erbrankheiten bislang ungeklärt. Eine Identifikation der genetischen Ursache einer Erkrankung ist jedoch essenziell, um zusätzliche invasive Tests vermeiden, adäquate Therapiemaßnahmen in die Wege leiten, akkurate Prognosen stellen und eine entsprechende genetische Beratung anbieten zu können. Next Generation Sequencing (NGS)-basierte Techniken wie die Whole Exome Sequenzierung (WES) haben die humangenetische Forschung und Diagnostik in den letzten Jahren revolutioniert. Die WES ermöglicht die Sequenzierung der Exons aller proteincodierenden Gene von mehreren Individuen gleichzeitig und stellt ein hilfreiches Werkzeug bei der Suche nach neuen kranheitsrelevanten Genen im Menschen dar.
Die vorliegende Arbeit beschäftigt sich mit der Aufklärung genetischer Ursachen verschiedenster Erkrankungen in konsanguinen Familien aus dem nahen und mittleren Osten mittels WES. Insgesamt wurden 43 Patienten mit unterschiedlichen Krankheitsbildern untersucht, darunter viele mit Skelettdysplasien oder Neuropathien. In 22 Fällen (51%) konnte die entsprechende krankheitsverursachende Mutation ausfindig gemacht werden. In 21% der aufgeklärten Fälle wurden Sequenzvarianten detektiert, die in der Literatur bereits als pathogen beschrieben wurden, während 63% bisher noch unbekannte Mutationen in bereits als krankheitsrelevant beschriebenen Genen darstellten. Zudem konnten im Rahmen dieser Arbeit drei neue, für den Menschen krankheitsrelevante Gene identifiziert werden, solute carrier family 10 member 7 (SLC10A7), T-box 4 (TBX4) und MIA SH3 domain ER export factor 3 (MIA3). SLC10A7 codiert für einen Transporter aus der Familie der solute carrier, der in der Plasmamembran verankert ist. In dieser Arbeit geleistete Analyseergebnisse konnten zu der Erstbeschreibung von homozygoten pathogenen SLC10A7-Mutationen als Ursache für eine Skelettdysplasie mit Amelogenesis imperfecta beitragen. Bei TBX4 handelt es sich um einen hochkonservierten Transkriptionsfaktor, der während der embryonalen Entwicklung an der Ausbildung der unteren Extremitäten beteiligt ist. Homozygote pathogene TBX4-Mutationen wurden im Kontext dieser Arbeit erstmalig mit einer posterioren Amelie mit Becken- und Lungenhypoplasie in Verbindung gebracht. MIA3 ist ein Transmembranprotein des endoplasmatischen Retikulums, das eine essenzielle Rolle bei der Proteinsekretion spielt. Die hier vorgestellten Patienten mit homozygoten pathogenen MIA3-Mutationen zeigen eine komplexe syndromale Erkrankung, die sich hauptsächlich in einer Kollagenopathie, Diabetes mellitus und milder mentaler Retardierung manifestiert und ein neues Krankheitsbild darstellt.
Die im Rahmen dieser Arbeit erzielten Ergebnisse erweitern somit zum einen das Mutationsspektrum verschiedener bekannter Krankheitsbilder und offenbaren zum anderen neue krankheitsrelevante Gene im Menschen.
N2 - Despite the rapid development of molecular genetic analysis methods, the causes of many hereditary diseases are still unknown. However, it is essential to identify the genetic cause of a disease in order to avoid additional invasive tests, to initiate adequate therapeutic measures, to be able to provdide accurate prognoses, and to offer appropriate genetic counselling. Over the past years, Next Generation Sequencing (NGS)-based technologies such as Whole Exome Sequencing (WES) have revolutionized research and diagnostics in human genetics. WES enables sequencing of the exons of all protein-coding genes from several individuals simultaneously and is a powerful tool in identifying new disease-relevant genes in humans.
The present work deals with the elucidation of genetic disease causes in consanguineous families from the Near and Middle East by means of WES. A total of 43 patients with various clinical phenotypes were examined, including many with skeletal dysplasias or neuropathies. In 22 cases (51%), the genetic cause of the disease could be found. In 21% of the solved cases, sequence variants were detected that were already described as pathogenic in the literature, while 63% showed previously unknown mutations in genes already described as disease-relevant in humans. In addition, three new disease-relevant genes could be identified within the scope of this work: solute carrier family 10 member 7 (SLC10A7), T-box 4 (TBX4) and MIA SH3 domain ER export factor 3 (MIA3). SLC10A7 encodes a transporter from the family of solute carriers, which is anchored in the plasma membrane. The analysis results performed in this study could contribute to the first description of homozygous pathogenic SLC10A7 mutations as the cause of a novel skeletal dysplasia with amelogenesis imperfecta. TBX4 is a highly conserved transcription factor that is involved in the formation of the lower extremities during embryonic development. Homozygous pathogenic TBX4 mutations were associated for the first time with posterior amelia with pelvic and pulmonary hypoplasia in the context of this study. MIA3 is a transmembrane protein of the endoplasmic reticulum that plays an essential role in the secretory pathway. The patients presented here with homozygous pathogenic MIA3 mutations show a complex syndromal disease manifesting mainly in a collagenopathy, diabetes mellitus, and mild mental retardation, representing a novel clinical picture.
The results obtained within the scope of this work expand on the one hand the range of mutations of various known diseases and on the other hand reveal novel disease-relevant genes in humans.
KW - Verwandtenehe
KW - Exomsequenzierung
KW - Konsanguinität
KW - autosomal rezessiver Erbgang
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208807
ER -
TY - THES
A1 - Reichenbach, Juliane Renate
T1 - Paternal age effects on sperm DNA methylation and its impact on the next generation
T1 - Der väterliche Alterseffekt auf das Spermienmethylom und seine Auswirkungen auf die nächste Generation
N2 - The effect of late parenthood on the offspring´s physical and mental health status has recently become an increasingly important topic of discussion. Studies on neurodevelopmental disorders in children of older parents (Naserbakht et al., 2011) outline the negative consequences of aging fathers as unpredictable compared to the better-understood unfavorable maternal influences (Cedars et al. 2015). This may be due to the fact that lifelong production of male gametes becomes more susceptible to error, not only for somatic mutations. Non-genomic mechanisms such as epigenetic methylation also alter DNA dynamically throughout life (Jones et al., 2015) and influence the aging human sperm DNA (Jenkins et al., 2014). These methylation changes may be transmitted to the next generation via epigenetic inheritance mechanisms (Milekic et al., 2015), which may negatively impact the sensitive epigenetic regulation of cell differentiation in the embryonic period (Curley et al., 2011; Spiers et al., 2015). Accordingly, Nardone et al. (2014) reported several hypomethylated regions in autistic patients, illustrating potential epigenetic influences on the multifactorial pathogenesis of neuropsychiatric disorders. In the present study, the methylation status of five gene regions in the sperm DNA of males of different ages was analyzed by two techniques - pyrosequencing and deep bisulfite sequencing. Two gene regions, FOXK1 and DMPK, showed a highly significant age-related methylation loss and FOXK1 a reduced methylation variation at the level of single alleles. In addition, the examined gene region of FOXK1 showed significant methylation changes in the fetal cord blood DNA of the respective offspring of the sperm donor. This fact suggests a transfer of age-related methylation loss to the next generation. Interestingly, a methylation analysis at the level of single alleles showed that the methylation loss was inherited exclusively by the father. FOXK1 is a transcription factor that plays an important role in the epigenetic regulation of the cell cycle during embryonic neuronal development (Huang et al., 2004; Wijchers et al., 2006). For this reason, the methylation status of FOXK1 in the blood of autistic patients and an age- and sex-matched control group was investigated. While both groups showed age-associated FOXK1 methylation loss, a faster dynamics of methylation change was observed in the autistic group. Although further studies are needed to uncover inheritance mechanisms of epigenetic information, the present results show an evident influence of age-related methylation changes on offspring. When advising future fathers, it is important to consider how the paternal epigenome is altered by aging and can have a negative impact on the developing embryo.
N2 - Die Auswirkungen einer späten Elternschaft auf die körperliche und geistige Gesundheit der Nachkommen wurde in letzter Zeit zunehmend diskutiert. Studien zu neurologischen Entwicklungsstörungen bei Kindern älterer Eltern (Naserbakht et al. 2011) skizzieren insbesondere die negativen Folgen alternder Väter (Cedars et al. 2015). Dies ist möglicherweise darauf zurückzuführen, dass die lebenslange Produktion männlicher Gameten im Laufe des Lebens nicht nur für somatische Mutationen fehleranfälliger wird. Auch nicht-genomische Mechanismen wie die epigenetische Methylierung verändert die DNA im Laufe des Lebens dynamisch (Jones et al. 2015) und beeinflussen die alternde menschliche Spermien-DNA (Jenkins et al. 2014). Möglicherweise werden diese Methylierungsveränderungen über epigenetische Vererbungsmechanismen an die nächste Generation übertragen (Milekic et al. 2015), was sich negativ auf die empfindliche epigenetische Regulation der Zelldifferenzierung in der Embryonalperiode auswirken kann (Curley et al. 2011; Spiers et al. 2015). Mögliche epigenetische Einflüsse auf die multifaktorielle Pathogenese neuropsychiatrischer Erkrankungen veranschaulichend, zeigten Nardone et al. (2014) mehrere hypomethylierte Regionen bei autistischen Patienten auf. In der vorliegenden Arbeit wurde der Methylierungsstatus von fünf Genregionen in der Spermien-DNA von Männern unterschiedlichen Alters durch zwei Techniken analysiert – das Pyrosequencing und das Deep Bisulfite Sequencing. Zwei Genregionen, FOXK1 und DMPK, zeigten einen hochgradig signifikanten altersbedingten Methylierungsverlust und FOXK1 auf der Ebene einzelner Allele eine verringerte Methylierungsvariation. Darüber hinaus zeigte die untersuchte Genregion von FOXK1 signifikante Methylierungsveränderungen in der Nabelschnurblut-DNA der jeweiligen Nachkommen der Samenspender. Diese Tatsache spricht für eine Übertragung des altersbedingten Methylierungsverlustes auf die nächste Generation.
Anhand einer Methylierungsanalyse auf der Ebene einzelner Allele konnte interessanterweise gezeigt werden, dass der Methylierungsverlust ausschließlich durch den Vater vererbt wurde. FOXK1 ist ein Transkriptionsfaktor, der eine wichtige Rolle bei der epigenetischen Regulation des Zellzyklus während der embryonalen neuronalen Entwicklung spielt (Huang et al. 2004; Wijchers et al. 2006). Aus diesem Grund wurde der Methylierungsstatus von FOXK1 im Blut autistischer Patienten und einer alters- und geschlechtsentsprechenden Kontrollgruppe untersucht. Während beide Gruppen einen altersassoziierten FOXK1-Methylierungverlust zeigten, wurde in der autistischen Gruppe eine schnellere Dynamik der Methylierungsänderung beobachtet. Obwohl weitere Studien erforderlich sind, um Vererbungsmechanismen epigenetischer Information aufzudecken, zeigen die vorliegenden Ergebnisse einen offensichtlichen Einfluss altersbedingter Methylierungsveränderungen auf die Nachkommen. Bei der Beratung zukünftiger Väter ist es wichtig zu berücksichtigen, wie das väterliche Epigenom durch das Altern verändert wird und negative Auswirkungen auf den sich entwickelnden Embryo haben kann.
KW - Epigenetik
KW - Vater
KW - Spermium
KW - Autismus
KW - Methylierung
KW - paternal age
KW - epigenetics
KW - sperm
KW - methylation
KW - reproduction
KW - autism
KW - Väterliches Alter
KW - Epigenetik
KW - Spermien
KW - Methylierung
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199805
ER -
TY - JOUR
A1 - Blättner, Sebastian
A1 - Das, Sudip
A1 - Paprotka, Kerstin
A1 - Eilers, Ursula
A1 - Krischke, Markus
A1 - Kretschmer, Dorothee
A1 - Remmele, Christian W.
A1 - Dittrich, Marcus
A1 - Müller, Tobias
A1 - Schuelein-Voelk, Christina
A1 - Hertlein, Tobias
A1 - Mueller, Martin J.
A1 - Huettel, Bruno
A1 - Reinhardt, Richard
A1 - Ohlsen, Knut
A1 - Rudel, Thomas
A1 - Fraunholz, Martin J.
T1 - Staphylococcus aureus Exploits a Non-ribosomal Cyclic Dipeptide to Modulate Survival within Epithelial Cells and Phagocytes
JF - PLoS Pathogens
N2 - Community-acquired (CA) Staphylococcus aureus cause various diseases even in healthy individuals. Enhanced virulence of CA-strains is partly attributed to increased production of toxins such as phenol-soluble modulins (PSM). The pathogen is internalized efficiently by mammalian host cells and intracellular S. aureus has recently been shown to contribute to disease. Upon internalization, cytotoxic S. aureus strains can disrupt phagosomal membranes and kill host cells in a PSM-dependent manner. However, PSM are not sufficient for these processes. Here we screened for factors required for intracellular S. aureus virulence. We infected escape reporter host cells with strains from an established transposon mutant library and detected phagosomal escape rates using automated microscopy. We thereby, among other factors, identified a non-ribosomal peptide synthetase (NRPS) to be required for efficient phagosomal escape and intracellular survival of S. aureus as well as induction of host cell death. By genetic complementation as well as supplementation with the synthetic NRPS product, the cyclic dipeptide phevalin, wild-type phenotypes were restored. We further demonstrate that the NRPS is contributing to virulence in a mouse pneumonia model. Together, our data illustrate a hitherto unrecognized function of the S. aureus NRPS and its dipeptide product during S. aureus infection.
KW - cell death
KW - cytotoxicity
KW - Staphylococcus aureus
KW - host cells
KW - neutrophils
KW - macrophages
KW - transposable elements
KW - epithelial cells
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-180380
VL - 12
IS - 9
ER -
TY - JOUR
A1 - Hansmann, T.
A1 - Heinzmann, J.
A1 - Wrenzycki, C.
A1 - Zechner, U.
A1 - Niemann, H.
A1 - Haaf, T.
T1 - Characterization of Differentially Methylated Regions in 3 Bovine Imprinted Genes: A Model for Studying Human Germ-Cell and Embryo Development
JF - Cytogenetic and Genome Research
N2 - Correct imprinting is crucial for normal fetal and placental development in mammals. Experimental evidence in animal models and epidemiological studies in humans suggest that assisted reproductive technologies (ARTs) can interfere with imprinted gene regulation in gametogenesis and early embryogenesis. Bos taurus is an agriculturally important species in which ARTs are commonly employed. Because this species exhibits a similar preimplantation development and gestation length as humans, it is increasingly being used as a model for human germ-cell and embryo development. However, in contrast to humans and mice, there is relatively little information on bovine imprinted genes. Here, we characterized the bovine intergenic IGF2-H19 imprinting control region (ICR) spanning approximately 3 kb. We identified a 300-bp differentially methylated region (DMR) approximately 6 kb upstream of the H19 promoter, containing a CpG island with CTCF-binding site and high sequence similarity with the human intergenic ICR. Additional differentially methylated CpG islands lie –6 kb to –3 kb upstream of the promoter, however these are less conserved. Both classical bisulfite sequencing and bisulfite pyrosequencing demonstrated complete methylation of the IGF2-H19 ICR in sperm, complete demethylation in parthenogenetic embryos having only the female genome, and differential methylation in placental and somatic tissues. In addition, we established pyrosequencing assays for the previously reported bovine SNRPN and PEG3 DMRs. The observed methylation patterns were consistent with genomic imprinting in all analyzed tissues/cell types. The identified IGF2-H19 ICR and the developed quantitative methylation assays may prove useful for further studies on the relationship between ARTs and imprinting defects in the bovine model.
KW - bovine
KW - differentially methylated region
KW - IGF2-H19
KW - imprinting control region
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199051
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 132
IS - 4
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
A1 - Winking, Heinz
T1 - Multicolor Spectral Analyses of Mitotic and Meiotic Mouse Chromosomes Involved in Multiple Robertsonian Translocations. I. The CD/Cremona Hybrid Strain
JF - Cytogenetic and Genome Research
N2 - Multicolor spectral analysis (spectral karyotyping) was applied to mitotic and male diakinetic chromosomes of hybrid mice carrying a unique system of 18 autosomal Robertsonian translocation chromosomes with alternating arm homologies. Only the autosomes 19 and the XY sex chromosomes are excluded from these Robertsonian translocations. The translocations, previously identified by conventional banding analyses, could be verified by spectral karyotyping. Besides the Robertsonian translocations, no other interchromosomal rearrangements were detected. In diakineses of male meiosis, the 18 metacentric Robertsonian translocation chromosomes form a very large meiotic ‘superring'. The predictable, specific order of the chromosomes along this ‘superring' was completely confirmed by multicolor spectral analysis. In the majority of diakineses analyzed, the free autosomal bivalent 19 and the XY sex bivalent form a conspicuous complex which tightly associates with the 12;14 Robertsonian translocation chromosome in the ‘superring'.
KW - meiotic ‘superring’
KW - mouse
KW - Robertsonian translocation chromosomes
KW - spectral karyotyping
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199013
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 147
IS - 4
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
T1 - Chromosome Banding in Amphibia. XXXIII. Demonstration of 5-Methylcytosine-Rich Heterochromatin in Anura
JF - Cytogenetic and Genome Research
N2 - An experimental approach using monoclonal anti-5-methylcytosine (5-MeC) antibodies and indirect immunofluorescence was elaborated for detecting 5-MeC-rich chromosome regions in anuran chromosomes. This technique was applied to mitotic metaphases of 6 neotropical frog species belonging to 6 genera and 4 families. The hypermethylation patterns were compared with a variety of banding patterns obtained by conventional banding techniques. The hypermethylated DNA sequences are species-specific and located exclusively in constitutive heterochromatin. They are found in centromeric, pericentromeric, telomeric, and interstitial positions of the chromosomes and adjacent to nucleolus organizer regions. 5-MeC-rich DNA sequences can be embedded both in AT- and GC-rich repetitive DNA. The experimental parameters that have major influence on the reproducibility and quality of the anti-5-MeC antibody labeling are discussed.
KW - Anura
KW - heterochromatin
KW - hypermethylated DNA
KW - immunofluorescence
KW - 5-Methylcytosine
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199022
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 148
IS - 1
ER -
TY - JOUR
A1 - Schneider, Eberhard
A1 - El Hajj, Nady
A1 - Müller, Fabian
A1 - Navarro, Bianca
A1 - Haaf, Thomas
T1 - Epigenetic Dysregulation in the Prefrontal Cortex of Suicide Completers
JF - Cytogenetic and Genome Research
N2 - The epigenome is thought to mediate between genes and the environment, particularly in response to adverse life experiences. Similar to other psychiatric diseases, the suicide liability of an individual appears to be influenced by many genetic factors of small effect size as well as by environmental stressors. To identify epigenetic marks associated with suicide, which is considered the endpoint of complex gene-environment interactions, we compared the cortex DNA methylation patterns of 6 suicide completers versus 6 non-psychiatric sudden-death controls, using Illumina 450K methylation arrays. Consistent with a multifactorial disease model, we found DNA methylation changes in a large number of genes, but no changes with large effects reaching genome-wide significance. Global methylation of all analyzed CpG sites was significantly (0.25 percentage point) lower in suicide than in control brains, whereas the vast majority (97%) of the top 1,000 differentially methylated regions (DMRs) were higher methylated (0.6 percentage point) in suicide brains. Annotation analysis of the top 1,000 DMRs revealed an enrichment of differentially methylated promoters in functional categories associated with transcription and expression in the brain. In addition, we performed a comprehensive literature research to identify suicide genes that have been replicated in independent genetic association, brain methylation and/or expression studies. Although, in general, there was no significant overlap between different published data sets or between our top 1,000 DMRs and published data sets, our methylation screen strengthens a number of candidate genes (APLP2, BDNF, HTR1A, NUAK1, PHACTR3, MSMP, SLC6A4, SYN2, and SYNE2) and supports a role for epigenetics in the pathophysiology of suicide.
KW - Cortex
KW - DNA methylation
KW - Suicidal behavior
KW - Transcription regulation
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199032
SN - 1424-8581
SN - 1424-859X
VL - 146
IS - 1
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
A1 - Haaf, Thomas
A1 - Mijares-Urrutia, Abraham
T1 - Nascent ZW Sex Chromosomes in Thecadactylus rapicauda (Reptilia, Squamata, Phyllodactylidae)
JF - Cytogenetic and Genome Research
N2 - The chromosomes of the turnip-tailed gecko Thecadactylus rapicauda from the Falcón State in northern Venezuela were examined by means of conventional staining, a variety of banding techniques and in situ hybridization with an 18S + 28S rDNA probe. In female specimens, C-banding analyses detected a cryptic W sex chromosome-associated interstitial heterochromatic segment which is absent in the Z sex chromosome. These ZW sex chromosomes are considered to be in a nascent stage of morphological differentiation and are absent in T. rapicauda collected in Guatemala. The amount, location and fluorochrome affinities of constitutive heterochromatin, the position of the nucleolus organizer region, and the genome sizes of female and male individuals were determined. The previously published cytogenetic data on T. rapicauda are discussed.
KW - ZW sex chromosomes
KW - Gecko
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199041
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 143
IS - 4
ER -
TY - JOUR
A1 - Lamatsch, D. K.
A1 - Trifonov, V.
A1 - Schories, S.
A1 - Epplen, J. T.
A1 - Schmid, M.
A1 - Schartl, M.
T1 - Isolation of a Cancer-Associated Microchromosome in the Sperm-Dependent Parthenogen Poecilia formosa
JF - Cytogenetic and Genome Research
N2 - In the asexual all-female fish species Poecilia formosa, the Amazon molly, supernumerary chromosomes have frequently been found in both laboratory-reared and wild-caught individuals. While wild-caught individuals with B chromosomes are phenotypically indifferent from conspecifics, individuals carrying B chromosomes from recent introgression events in the laboratory show phenotypic changes. Former analyses showed that the expression of a pigment cell locus is associated with the presence of these B chromosomes. In addition, they contain a so far unidentified locus that confers a higher susceptibility to tumor formation in the presence of pigmentation pattern. Isolation by microdissection and hybridization to metaphase chromosomes revealed that they contain one or several sequences with similarity to a highly repetitive pericentromeric and subtelomeric sequence in A chromosomes. Isolation of one particular sequence by AFLP showed that the B chromosomes contain at least 1 copy of an A-chromosomal region which is highly conserved in the whole genus Poecilia, i.e. more than 5 million years old. We propose it to be a single copy sequence.
KW - paternal introgression
KW - AFLP
KW - asexual reproduction
KW - B chromosomes
KW - gynogenesis
KW - microdissection
KW - telomeres
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196785
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 135
IS - 2
ER -
TY - JOUR
A1 - Schneider, Eberhard
A1 - El Hajj, Nady
A1 - Haaf, Thomas
T1 - Epigenetic Information from Ancient DNA Provides New Insights into Human Evolution
BT - Commentary on Gokhman D et al. (2014): Reconstructing the DNA
Methylation Maps of the Neanderthal and the Denisovan. Science 344:523–527
JF - Brain, Behavior and Evolution
N2 - No abstract available.
KW - human evolution
KW - Neanderthal
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196800
SN - 0006-8977
SN - 1421-9743
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 84
IS - 3
ER -
TY - JOUR
A1 - Camacho, J.P.M.
A1 - Schmid, M.
A1 - Cabrero, J.
T1 - B Chromosomes and Sex in Animals
JF - Sexual Development
N2 - Supernumerary (B) chromosomes are dispensable elements found in many eukaryote genomes in addition to standard (A) chromosomes. In many respects, B chromosomes resemble sex chromosomes, so that a common ancestry for them has frequently been suggested. For instance, B chromosomes in grasshoppers, and other insects, show a pycnotic cycle of condensation-decondensation during meiosis remarkably similar to that of the X chromosome. In some cases, B chromosome size is even very similar to that of the X chromosome. These resemblances have led to suggest the X as the B ancestor in many cases. In addition, sex chromosome origin from B chromosomes has also been suggested. In this article, we review the existing evidence for both evolutionary pathways, as well as sex differences for B frequency at adult and embryo progeny levels, B chromosome effects or B chromosome transmission. In addition, we review cases found in the literature showing sex-ratio distortion associated with B chromosome presence, the most extreme case being the paternal sex ratio (PSR) chromosomes in some Hymenoptera. We finally analyse the possibility of B chromosome regularisation within the host genome and, as a consequence of it, whether B chromosomes can become regular members of the host genome.
KW - A chromosomes
KW - B chromosomes
KW - sex ratio
KW - X chromosome
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196321
SN - 1661-5425
SN - 1661-5433
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 5
IS - 3
ER -
TY - JOUR
A1 - Poot, Martin
A1 - Haaf, Thomas
T1 - Mechanisms of Origin, Phenotypic Effects and Diagnostic Implications of Complex Chromosome Rearrangements
JF - Molecular Syndromology
N2 - Complex chromosome rearrangements (CCRs) are currently defined as structural genome variations that involve more than 2 chromosome breaks and result in exchanges of chromosomal segments. They are thought to be extremely rare, but their detection rate is rising because of improvements in molecular cytogenetic technology. Their population frequency is also underestimated, since many CCRs may not elicit a phenotypic effect. CCRs may be the result of fork stalling and template switching, microhomology-mediated break-induced repair, breakage-fusion-bridge cycles, or chromothripsis. Patients with chromosomal instability syndromes show elevated rates of CCRs due to impaired DNA double-strand break responses during meiosis. Therefore, the putative functions of the proteins encoded by ATM, BLM, WRN, ATR, MRE11, NBS1, and RAD51 in preventing CCRs are discussed. CCRs may exert a pathogenic effect by either (1) gene dosage-dependent mechanisms, e.g. haploinsufficiency, (2) mechanisms based on disruption of the genomic architecture, such that genes, parts of genes or regulatory elements are truncated, fused or relocated and thus their interactions disturbed - these mechanisms will predominantly affect gene expression - or (3) mixed mutation mechanisms in which a CCR on one chromosome is combined with a different type of mutation on the other chromosome. Such inferred mechanisms of pathogenicity need corroboration by mRNA sequencing. Also, future studies with in vitro models, such as inducible pluripotent stem cells from patients with CCRs, and transgenic model organisms should substantiate current inferences regarding putative pathogenic effects of CCRs. The ramifications of the growing body of information on CCRs for clinical and experimental genetics and future treatment modalities are briefly illustrated with 2 cases, one of which suggests KDM4C(JMJD2C) as a novel candidate gene for mental retardation.
KW - triplosufficiency
KW - complex chromosome rearrangements
KW - DNA double-strand break
KW - haploinsufficiency
KW - mixed mutation mechanisms
KW - structural genome variations
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196524
SN - 1661-8769
SN - 1661-8777
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 6
IS - 3
ER -
TY - JOUR
A1 - Heinrich, T.
A1 - Nanda, I.
A1 - Rehn, M.
A1 - Zollner, U.
A1 - Frieauff, E.
A1 - Wirbelauer, J.
A1 - Grimm, T.
A1 - Schmid, M.
T1 - Live-Born Trisomy 22: Patient Report and Review
JF - Molecular Syndromology
N2 - Trisomy 22 is a common trisomy in spontaneous abortions. In contrast, live-born trisomy 22 is rarely seen due to severe organ malformations associated with this condition. Here, we report on a male infant with complete, non-mosaic trisomy 22 born at 35 + 5 weeks via caesarean section. Peripheral blood lymphocytes and fibroblasts showed an additional chromosome 22 in all metaphases analyzed (47,XY,+22). In addition, array CGH confirmed complete trisomy 22. The patient’s clinical features included dolichocephalus, hypertelorism, flattened nasal bridge, dysplastic ears with preauricular sinuses and tags, medial cleft palate, anal atresia, and coronary hypospadias with scrotum bipartitum. Essential treatment was implemented in close coordination with the parents. The child died 29 days after birth due to respiratory insufficiency and deterioration of renal function. Our patient’s history complements other reports illustrating that children with complete trisomy 22 may survive until birth and beyond.
KW - chromosomal abnormality
KW - live-born
KW - non-mosaic
KW - trisomy 22
Y1 - 2013
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196535
SN - 1661-8769
SN - 1661-8777
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 3
IS - 6
ER -
TY - JOUR
A1 - Almanzar, Giovanni
A1 - Klein, Matthias
A1 - Schmalzing, Marc
A1 - Hilligardt, Deborah
A1 - El Hajj, Nady
A1 - Kneitz, Hermann
A1 - Wild, Vanessa
A1 - Rosenwald, Andreas
A1 - Benoit, Sandrine
A1 - Hamm, Henning
A1 - Tony, Hans-Peter
A1 - Haaf, Thomas
A1 - Goebeler, Matthias
A1 - Prelog, Martina
T1 - Disease Manifestation and Inflammatory Activity as Modulators of Th17/Treg Balance and RORC/FoxP3 Methylation in Systemic Sclerosis
JF - International Archives of Allergy and Immunology
N2 - Background: There is much evidence that T cells are strongly involved in the pathogenesis of localized and systemic forms of scleroderma (SSc). A dysbalance between FoxP3+ regulatory CD4+ T cells (Tregs) and inflammatory T-helper (Th) 17 cells has been suggested. Methods: The study aimed (1) to investigate the phenotypical and functional characteristics of Th17 and Tregs in SSc patients depending on disease manifestation (limited vs. diffuse cutaneous SSc, dcSSc) and activity, and (2) the transcriptional level and methylation status of Th17- and Treg-specific transcription factors. Results: There was a concurrent accumulation of circulating peripheral IL-17-producing CCR6+ Th cells and FoxP3+ Tregs in patients with dcSSc. At the transcriptional level, Th17- and Treg-associated transcription factors were elevated in SSc. A strong association with high circulating Th17 and Tregs was seen with early, active, and severe disease presentation. However, a diminished suppressive function on autologous lymphocytes was found in SSc-derived Tregs. Significant relative hypermethylation was seen at the gene level for RORC1 and RORC2 in SSc, particularly in patients with high inflammatory activity. Conclusions: Besides the high transcriptional activity of T cells, attributed to Treg or Th17 phenotype, in active SSc disease, Tregs may be insufficient to produce high amounts of IL-10 or to control proliferative activity of effector T cells in SSc. Our results suggest a high plasticity of Tregs strongly associated with the Th17 phenotype. Future directions may focus on enhancing Treg functions and stabilization of the Treg phenotype.
KW - methylation
KW - systemic sclerosis
KW - suppression
KW - Tregs
KW - Th17
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196577
SN - 1018-2438
SN - 1423-0097
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 171
IS - 2
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
T1 - Chromosome Banding in Amphibia. XXXIV. Intrachromosomal Telomeric DNA Sequences in Anura
JF - Cytogenetic and Genome Research
N2 - The mitotic chromosomes of 4 anuran species were examined by various classical banding techniques and by fluorescence in situ hybridization using a (TTAGGG)\(_n\) repeat. Large intrachromosomal telomeric sequences (ITSs) were demonstrated in differing numbers and chromosome locations. A detailed comparison of the present results with numerous published and unpublished data allowed a consistent classification of the various categories of large ITSs present in the genomes of anurans and other vertebrates. The classification takes into consideration the total numbers of large ITSs in the karyotypes, their chromosomal locations and their specific distribution patterns. A new category of large ITSs was recognized to exist in anuran species. It consists of large clusters of ITSs located in euchromatic chromosome segments, which is in clear contrast to the large ITSs in heterochromatic chromosome regions known in vertebrates. The origin of the different categories of large ITSs in heterochromatic and euchromatic chromosome regions, their mode of distribution in the karyotypes and evolutionary fixation in the genomes, as well as their cytological detection are discussed.
KW - heterochromatin
KW - intrachromosomal telomeric sequences
KW - Anura
KW - euchromatin
KW - evolutionary fixation
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196693
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 148
IS - 2-3
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
A1 - Lomb, Christian
A1 - Sperling, Karl
A1 - Neitzel, Heidemarie
T1 - 5-Methylcytosine-Rich Heterochromatin in the Indian Muntjac
JF - Cytogenetic and Genome Research
N2 - Two 5-methylcytosine (5-MeC)-rich heterochromatic regions were demonstrated in metaphase chromosomes of the Indian muntjac by indirect immunofluorescence using a monoclonal anti-5-MeC antibody. The metaphases were obtained from diploid and triploid cell lines. A major region is located in the ‘neck' of the 3;X fusion chromosome and can be detected after denaturation of the chromosomal DNA with UV-light irradiation for 1 h. It is located exactly at the border of the X chromosome and the translocated autosome 3. A minor region is found in the centromeric region of the free autosome 3 after denaturing the chromosomal DNA for 3 h or longer. The structure and possible function of the major hypermethylated region as barrier against spreading of the X-inactivation process into the autosome 3 is discussed.
KW - heterochromatin
KW - immunofluorescence
KW - Indian muntjac
KW - 5-Methylcytosine
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196701
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 147
IS - 4
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
A1 - Yano, Cassia F.
A1 - Cioffi, Marcelo B.
T1 - Hypermethylated Chromosome Regions in Nine Fish Species with Heteromorphic Sex Chromosomes
JF - Cytogenetic and Genome Research
N2 - Sites and amounts of 5-methylcytosine (5-MeC)-rich chromosome regions were detected in the karyotypes of 9 Brazilian species of Characiformes fishes by indirect immunofluorescence using a monoclonal anti-5-MeC antibody. These species, belonging to the genera Leporinus, Triportheus and Hoplias, are characterized by highly differentiated and heteromorphic ZW and XY sex chromosomes. In all species, the hypermethylated regions are confined to constitutive heterochromatin. The number and chromosome locations of hypermethylated heterochromatic regions in the karyotypes are constant and species-specific. Generally, heterochromatic regions that are darkly stained by the C-banding technique are distinctly hypermethylated, but several of the brightly fluorescing hypermethylated regions merely exhibit moderate or faint C-banding. The ZW and XY sex chromosomes of all 9 analyzed species also show species-specific heterochromatin hypermethylation patterns. The analysis of 5-MeC-rich chromosome regions contributes valuable data for comparative cytogenetics of closely related species and highlights the dynamic process of differentiation operating in the repetitive DNA fraction of sex chromosomes.
KW - heterochromatin
KW - heteromorphic sex chromosomes
KW - hypermethylation
KW - immunofluorescence
KW - 5-Methylcytosine
KW - fish
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196710
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 147
IS - 2-3
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
T1 - Chromosome Banding in Amphibia. XXXII. The Genus Xenopus (Anura, Pipidae)
JF - Cytogenetic and Genome Research
N2 - Mitotic chromosomes of 16 species of the frog genus Xenopus were prepared from kidney and lung cell cultures. In the chromosomes of 7 species, high-resolution replication banding patterns could be induced by treating the cultures with 5-bromodeoxyuridine (BrdU) and deoxythymidine (dT) in succession, and in 6 of these species the BrdU/dT-banded chromosomes could be arranged into karyotypes. In the 3 species of the clade with 2n = 20 and 4n = 40 chromosomes (X. tropicalis, X. epitropicalis, X. new tetraploid 1), as well as in the 3 species with 4n = 36 chromosomes (X. laevis, X. borealis, X. muelleri), the BrdU/dT-banded karyotypes show a high degree of homoeology, though differences were detected between these groups. Translocations, inversions, insertions or sex-specific replication bands were not observed. Minor replication asynchronies found between chromosomes probably involve heterochromatic regions. BrdU/dT replication banding of Xenopus chromosomes provides the landmarks necessary for the exact physical mapping of genes and repetitive sequences. FISH with an X. laevis 5S rDNA probe detected multiple hybridization sites at or near the long-arm telomeric regions in most chromosomes of X. laevis and X. borealis, whereas in X. muelleri, the 5S rDNA sequences are located exclusively at the long-arm telomeres of a single chromosome pair. Staining with the AT base pair-specific fluorochrome quinacrine mustard revealed brightly fluorescing heterochromatic regions in the majority of X. borealis chromosomes which are absent in other Xenopus species.
KW - X. laevis-type karyotype
KW - X. tropicalis-type karyotype
KW - BrdU/dT replication banding
KW - chromosome staining
KW - FISH
KW - polyploidy
KW - Xenopus
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196727
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 145
IS - 3-4
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Evans, Ben J.
A1 - Bogart, James P.
T1 - Polyploidy in Amphibia
JF - Cytogenetic and Genome Research
N2 - This review summarizes the current status of the known extant genuine polyploid anuran and urodelan species, as well as spontaneously originated and/or experimentally produced amphibian polyploids. The mechanisms by which polyploids can originate, the meiotic pairing configurations, the diploidization processes operating in polyploid genomes, the phenomenon of hybridogenesis, and the relationship between polyploidization and sex chromosome evolution are discussed. The polyploid systems in some important amphibian taxa are described in more detail.
KW - allopolyploidy
KW - Anura
KW - autopolyploidy
KW - diploidization
KW - hybridogenesis
KW - polyploidization
KW - sex chromosome evolution
KW - Urodela
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196730
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 145
IS - 3-4
ER -
TY - JOUR
A1 - Matsuda, Yoichi
A1 - Uno, Yoshinobu
A1 - Kondo, Mariko
A1 - Gilchrist, Michael J.
A1 - Zorn, Aaron M.
A1 - Rokhsar, Daniel S.
A1 - Schmid, Michael
A1 - Taira, Masanori
T1 - A New Nomenclature of Xenopus laevis Chromosomes Based on the Phylogenetic Relationship to Silurana/Xenopus tropicalis
JF - Cytogenetic and Genome Research
N2 - Xenopus laevis (XLA) is an allotetraploid species which appears to have undergone whole-genome duplication after the interspecific hybridization of 2 diploid species closely related to Silurana/Xenopus tropicalis (XTR). Previous cDNA fluorescence in situ hybridization (FISH) experiments have identified 9 sets of homoeologous chromosomes in X. laevis, in which 8 sets correspond to chromosomes 1-8 of X. tropicalis (XTR1-XTR8), and the last set corresponds to a fusion of XTR9 and XTR10. In addition, recent X. laevis genome sequencing and BAC-FISH experiments support this physiological relationship and show no gross chromosome translocation in the X. laevis karyotype. Therefore, for the benefit of both comparative cytogenetics and genome research, we here propose a new chromosome nomenclature for X. laevis based on the phylogenetic relationship and chromosome length, i.e. XLA1L, XLA1S, XLA2L, XLA2S, and so on, in which the numbering of XLA chromosomes corresponds to that in X. tropicalis and the postfixes ‘L' and ‘S' stand for ‘long' and ‘short' chromosomes in the homoeologous pairs, which can be distinguished cytologically by their relative size. The last chromosome set is named XLA9L and XLA9S, in which XLA9 corresponds to both XTR9 and XTR10, and hence, to emphasize the phylogenetic relationship to X. tropicalis, XLA9_10L and XLA9_10S are also used as synonyms.
KW - BrdU replication banding pattern
KW - homoeologous chromosomes
KW - nomenclature
KW - Xenopus laevis
KW - Xenopus tropicalis
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196748
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 145
IS - 3-4
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
A1 - Feichtinger, Wolfgang
A1 - Haaf, Thomas
A1 - Mijares-Urrutia, Abraham
A1 - Schargel, Walter E.
A1 - Hedges, S. Blair
T1 - Cytogenetic Studies on Gonatodes (Reptilia, Squamata, Sphaerodactylidae)
JF - Cytogenetic and Genome Research
N2 - Mitotic and meiotic chromosomes of 5 species of the reptile genus Gonatodes are described by means of conventional staining, banding analyses and in situ hybridization using a synthetic telomeric DNA probe. The amount, location and fluorochrome affinities of constitutive heterochromatin, the number and positions of nucleolus organizer regions, and the patterns of telomeric DNA sequences were determined for most of the species. The karyotypes of G. falconensis and G. taniae from northern Venezuela are distinguished by their extraordinarily reduced diploid chromosome number of 2n = 16, which is the lowest value found so far in reptiles. In contrast to most other reptiles, both species have exclusively large biarmed (meta- and submetacentric) chromosomes. Comparison of the karyotypes of G. falconensis and G. taniae with those of other Gonatodes species indicates that the exceptional 2n = 16 karyotype originated by a series of 8 centric fusions. The karyotypes of G. falconensis and G. taniae are further characterized by the presence of considerable amounts of (TTAGGG)n telomeric sequences in the centromeric regions of all chromosomes. These are probably not only relics of the centric fusion events, but a component of the highly repetitive DNA in the constitutive heterochromatin of the chromosomes. The genome sizes of 4 Gonatodes species were determined using flow cytometry. For comparative purposes, all previously published cytogenetic data on Gonatodes and other sphaerodactylids are included and discussed.
KW - banding analyses
KW - FISH
KW - geckos
KW - karyotype evolution
KW - meiotic chromosomes
KW - mitotic chromosomes
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196753
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 144
IS - 1
ER -
TY - JOUR
A1 - Schmid, Michael
A1 - Steinlein, Claus
A1 - Feichtinger, Wolfgang
A1 - Bogart, James P.
T1 - Chromosome Banding in Amphibia. XXXI. The Neotropical Anuran Families Centrolenidae and Allophrynidae
JF - Cytogenetic and Genome Research
N2 - The mitotic chromosomes of 11 species from the anuran families Centrolenidae and Allophrynidae were analyzed by means of conventional staining, banding techniques, and in situ hybridization. The amount, location, and fluorochrome affinities of constitutive heterochromatin, the number and positions of nucleolus organizer regions, and the patterns of telomeric DNA sequences were determined for most of the species. The karyotypes were found to be highly conserved with a low diploid chromosome number of 2n = 20 and morphologically similar chromosomes. The sister group relationship between the Centrolenidae and Allophrynidae (unranked taxon Allocentroleniae) is clearly corroborated by the cytogenetic data. The existence of heteromorphic XY♂/XX♀ sex chromosomes in an initial stage of morphological differentiation was confirmed in Vitreorana antisthenesi. The genome sizes of 4 centrolenid species were determined using flow cytometry. For completeness and for comparative purposes, all previously published cytogenetic data on centrolenids are included.
KW - Allophrynidae
KW - Anura
KW - chromosome evolution
KW - sex chromosomes
KW - Centrolenidae
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196763
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 142
IS - 4
ER -
TY - JOUR
A1 - Focken, T.
A1 - Steinemann, D.
A1 - Skawran, B.
A1 - Hofmann, W.
A1 - Ahrens, P.
A1 - Arnold, N.
A1 - Kroll, P.
A1 - Kreipe, H.
A1 - Schlegelberger, B.
A1 - Gadzicki, D.
T1 - Human BRCA1-associated breast cancer: No increase in numerical chromosomal instability compared to sporadic tumors
JF - Cytogenetic and Genome Research
N2 - BRCA1 is a major gatekeeper of genomic stability. Acting in multiple central processes like double-strand break repair, centrosome replication, and checkpoint control, BRCA1 participates in maintaining genomic integrity and protects the cell against genomic instability. Chromosomal instability (CIN) as part of genomic instability is an inherent characteristic of most solid tumors and is also involved in breast cancer development. In this study, we determined the extent of CIN in 32 breast cancer tumors of women with a BRCA1 germline mutation compared to 62 unselected breast cancers. We applied fluorescence in situ hybridization (FISH) with centromere-specific probes for the chromosomes 1, 7, 8, 10, 17, and X and locus-specific probes for 3q27 (BCL6), 5p15.2 (D5S23), 5q31 (EGR1), 10q23.3 (PTEN), and 14q32 (IGH@) on formalin-fixed paraffin-embedded tissue microarray sections. Our hypothesis of an increased level of CIN in BRCA1-associated breast cancer could not be confirmed by this approach. Surprisingly, we detected no significant difference in the extent of CIN in BRCA1-mutated versus sporadic tumors. The only exception was the CIN value for chromosome 1. Here, the extent of CIN was slightly higher in the group of sporadic tumors.
KW - Hereditary breast cancer
KW - BRCA1
KW - Chromosomal instability
KW - CIN
KW - Fluorescence in situ hybridization
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196770
SN - 1424-8581
SN - 1424-859X
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 135
IS - 2
SP - 84
EP - 92
ER -
TY - THES
A1 - Engel, Jakob
T1 - Untersuchung der Korrelation von Genotyp und Phänotyp bei der Hypophosphatasie
T1 - Investigation of the correlation of genotype and phenotype in hypophosphatasia
N2 - Die Arbeit zeigt, dass die Symptome der HPP sehr variabel und unterschiedlich stark auftreten können. Dies erschwert die klinische Diagnosestellung der Erkrankung. Nahezu alle Patienten berichteten von starken Knochen-, Gelenk,- und Muskelschmerzen, von Karies und Parodontose sowie von vermehrten Frakturen, die zum Teil weitere chronische Schmerzen und Wiederholungsfrakturen erzeugen. Eine deutlich verminderte Leistungsfähigkeit im Vergleich zu Gleichaltrigen wurde ebenso häufig angegeben. Es konnte keine eindeutige Phänotyp - Genotyp Korrelation gefunden werden, allerdings geben die Daten einen deutlichen Hinweis, dass Patienten mit zwei Mutationen am stärksten symptomatisch betroffen sind.
Ebenfalls konnten keine Unterschiede zwischen dominant negativen Mutationen und nicht dominant negativen Mutationen gefunden werden.
N2 - The work shows that the symptoms of HPP can be very variable and vary greatly.
Almost all patients reported severe bone, joint, and muscle pain, caries and periodontal disease, as well as increased fractures, some of which produced further chronic pain and recurrent fractures.
Significantly reduced performance compared to peers was also reported frequently. No definite phenotype - genotype correlation could be found, but the data provide a clear indication that patients with two mutations are most symptomatically affected. Also, no differences between dominant negative mutations and non-dominant negative mutations could be found.
KW - Hypophosphatasie
KW - Korrelation
KW - Genotyp
KW - Phänotyp
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-181751
ER -
TY - JOUR
A1 - Maierhofer, Anna
A1 - Flunkert, Julia
A1 - Oshima, Junko
A1 - Martin, George M.
A1 - Poot, Martin
A1 - Nanda, Indrajit
A1 - Dittrich, Marcus
A1 - Müller, Tobias
A1 - Haaf, Thomas
T1 - Epigenetic signatures of Werner syndrome occur early in life and are distinct from normal epigenetic aging processes
JF - Aging Cell
N2 - Werner Syndrome (WS) is an adult‐onset segmental progeroid syndrome. Bisulfite pyrosequencing of repetitive DNA families revealed comparable blood DNA methylation levels between classical (18 WRN‐mutant) or atypical WS (3 LMNA‐mutant and 3 POLD1‐mutant) patients and age‐ and sex‐matched controls. WS was not associated with either age‐related accelerated global losses of ALU, LINE1, and α‐satellite DNA methylations or gains of rDNA methylation. Single CpG methylation was analyzed with Infinium MethylationEPIC arrays. In a correspondence analysis, atypical WS samples clustered together with the controls and were clearly separated from classical WS, consistent with distinct epigenetic pathologies. In classical WS, we identified 659 differentially methylated regions (DMRs) comprising 3,656 CpG sites and 613 RefSeq genes. The top DMR was located in the HOXA4 promoter. Additional DMR genes included LMNA, POLD1, and 132 genes which have been reported to be differentially expressed in WRN‐mutant/depleted cells. DMRs were enriched in genes with molecular functions linked to transcription factor activity and sequence‐specific DNA binding to promoters transcribed by RNA polymerase II. We propose that transcriptional misregulation of downstream genes by the absence of WRN protein contributes to the variable premature aging phenotypes of WS. There were no CpG sites showing significant differences in DNA methylation changes with age between WS patients and controls. Genes with both WS‐ and age‐related methylation changes exhibited a constant offset of methylation between WRN‐mutant patients and controls across the entire analyzed age range. WS‐specific epigenetic signatures occur early in life and do not simply reflect an acceleration of normal epigenetic aging processes.
KW - (classical and atypical) Werner syndrome
KW - bisulfite pyrosequencing
KW - methylation array
KW - premature aging
KW - segmental progeria
KW - transcription deficiency
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202733
VL - 18
ER -
TY - JOUR
A1 - El Hajj, Nady
A1 - Dittrich, Marcus
A1 - Böck, Julia
A1 - Kraus, Theo F. J.
A1 - Nanda, Indrajit
A1 - Müller, Tobias
A1 - Seidmann, Larissa
A1 - Tralau, Tim
A1 - Galetzka, Danuta
A1 - Schneider, Eberhard
A1 - Haaf, Thomas
T1 - Epigenetic dysregulation in the developing Down syndrome cortex
JF - Epigenetics
N2 - Using Illumina 450K arrays, 1.85% of all analyzed CpG sites were significantly hypermethylated and 0.31% hypomethylated in fetal Down syndrome (DS) cortex throughout the genome. The methylation changes on chromosome 21 appeared to be balanced between hypo- and hyper-methylation, whereas, consistent with prior reports, all other chromosomes showed 3-11times more hyper- than hypo-methylated sites. Reduced NRSF/REST expression due to upregulation of DYRK1A (on chromosome 21q22.13) and methylation of REST binding sites during early developmental stages may contribute to this genome-wide excess of hypermethylated sites. Upregulation of DNMT3L (on chromosome 21q22.4) could lead to de novo methylation in neuroprogenitors, which then persists in the fetal DS brain where DNMT3A and DNMT3B become downregulated. The vast majority of differentially methylated promoters and genes was hypermethylated in DS and located outside chromosome 21, including the protocadherin gamma (PCDHG) cluster on chromosome 5q31, which is crucial for neural circuit formation in the developing brain. Bisulfite pyrosequencing and targeted RNA sequencing showed that several genes of PCDHG subfamilies A and B are hypermethylated and transcriptionally downregulated in fetal DS cortex. Decreased PCDHG expression is expected to reduce dendrite arborization and growth in cortical neurons. Since constitutive hypermethylation of PCDHG and other genes affects multiple tissues, including blood, it may provide useful biomarkers for DS brain development and pharmacologic targets for therapeutic interventions.
KW - trisomy 21
KW - DNA methylation
KW - Down syndrome
KW - fetal brain development
KW - frontal cortex
KW - protocadherin gamma cluster
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191239
VL - 11
IS - 8
ER -
TY - THES
A1 - Patzina, Tobias
T1 - Genetische Veränderungen am SOX9 Lokus bei Pierre-Robin-Sequenz
T1 - Genetic variations at the SOX9 lokus in patients with Pierre-Robin-Sequence
N2 - Die Pierre-Robin-Sequenz ist eine angeborene kraniofaziale Fehlbildung, bei der häufig eine Triade von Symptomen, bestehend aus mandibulärer Mikrognathie/Retrognathie, Glossoptose und einer Gaumenspalte, beobachtet werden kann. Aufgrund der Heterogenität der PRS und der häufigen Vergesellschaftung mit Syndromen, konnten Ätiologie und Pathogenese der PRS bisher nur unzureichend geklärt werden. Für einen Teil der Patienten mit isolierter PRS konnte eine familiäre Häufung von PRS-Fällen nachgewiesen werden, was auf eine erbliche Komponente als krankheitsauslösenden Faktor hinweist. In diesem Zusammenhang konnten bei Patienten mit isolierter PRS gehäuft genetische Veränderungen mit einer Entfernung von über 1Mb zentromerisch (5´) von SOX9 auf dem Chromosom 17 detektiert werden. Es wird vermutet, dass diese genetischen Aberrationen am SOX9 Lokus eine gewebsspezifische Fehlregulation von SOX9 während der Embryonalentwicklung auslösen und somit ursächlich für die Entstehung von PRS sein können.
Das Ziel dieser Arbeit war es, eine Würzburger Patientenkohorte mit isolierter PRS zu gewinnen und Informationen über die phänotypischen Merkmale der Studienteilnehmer auszuwerten. Im Anschluss sollte die Patienten-DNS mittels molekulargenetischen Analysemethoden auf potenziell krankheitsauslösende genetische Aberrationen am SOX9 Lokus untersucht werden.
Zunächst konnte eine Kohorte mit sieben PRS-Patienten erstellt und Informationen über die phänotypischen Krankheitsmerkmale erfasst und ausgewertet werden. Anschließend wurden bei den Studienteilnehmern eine Array-CGH, eine quantitative Echtzeit-Polymerase-Kettenreaktion und im Bereich von drei konservierten, potenziell regulatorischen Elementen des SOX9 Lokus eine Sanger Sequenzierung durchgeführt. Die Array-CGH ergab zunächst bei einem Patienten zwei große Deletionen im regulativen Umfeld des SOX9 Lokus, welche im Weiteren nicht durch qPCR bestätigt werden konnten. Letztendlich konnten durch die Sanger Sequenzierung 22 Varianten detektiert werden, wovon für drei Einzelnukleotid-Polymorphismen eine prädisponierende Wirkung diskutierbar und für zwei Einzelnukleotid-Varianten eine ursächlich pathogene Wirkung nicht auszuschließen ist.
N2 - The Pierre-Robin-Sequence is a congenital craniofacial disorder mostly described as a triade of symptoms, consisting of mandibular micrognathia, glossoptosis and cleft palate. Due to its heterogenity, the aetiology and pathogenesis of PRS is not recognized in every case of the disease. Nevertheless familial accumulation in isolated PRS cases pointed to a possible genetic source of pathology. In this context, genetic analysis in patients with isolated PRS pointed to genetic variations far upstream (more than 1Mb) of the SOX9 gene on chromosome 17 as possibly disease-inducing. These genetic variations at the SOX9 lokus are supected to cause tissue specific misregulation of SOX9 during embryogenesis and thus can be seen as causal for the development of isolated PRS.
The objective of this study was to form a group of patients with isolated PRS and to gain information about their phenotype. Subsequently, genetic analysis should be used to find potentially disease inducing genetic variations at the SOX9 lokus.
A cohort of 7 patients with isolated PRS was formed and the phenotypes of these patients were registered and evaluated. In addition, array-CGH, real-time quantitative polymerase chain reaction and sanger sequencing was performed for all the participants of this study. Array-CGH resulted in two big deletions within the regulary domain of the SOX9 lokus, which could not be confirmed with qPCR. Eventually, sanger sequencing of three conserved, non coding elements at the SOX9 lokus showed 22 variants, of which three single-nucleotid polymorphisms could potentially prove to have a predisposing effect and two singlenucleotid-variants, for which a pathogenic effect cannot be ruled out.
KW - Robin-Syndrom
KW - Mikroarray
KW - CNV
KW - Sanger Sequenzierung
KW - Sanger sequencing
KW - quantitative Polymerasekettenreaktion
KW - qPCR
KW - Mikroarray
KW - SOX9
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186893
ER -
TY - JOUR
A1 - Martrat, Griselda
A1 - Maxwell, Christopher A.
A1 - Tominaga, Emiko
A1 - Porta-de-la-Riva, Montserrat
A1 - Bonifaci, Núria
A1 - Gómez-Baldó, Laia
A1 - Bogliolo, Massimo
A1 - Lázaro, Conxi
A1 - Blanco, Ignacio
A1 - Brunet, Joan
A1 - Neveling, Kornelia
A1 - et al,
T1 - Exploring the link between MORF4L1 and risk of breast cancer
JF - Breast Cancer Research
N2 - Introduction:
Proteins encoded by Fanconi anemia (FA) and/or breast cancer (BrCa) susceptibility genes cooperate in a common DNA damage repair signaling pathway. To gain deeper insight into this pathway and its influence on cancer risk, we searched for novel components through protein physical interaction screens.
Methods:
Protein physical interactions were screened using the yeast two-hybrid system. Co-affinity purifications and endogenous co-immunoprecipitation assays were performed to corroborate interactions. Biochemical and functional assays in human, mouse and Caenorhabditis elegans models were carried out to characterize pathway components. Thirteen FANCD2-monoubiquitinylation-positive FA cell lines excluded for genetic defects in the downstream pathway components and 300 familial BrCa patients negative for BRCA1/2 mutations were analyzed for genetic mutations. Common genetic variants were genotyped in 9,573 BRCA1/2 mutation carriers for associations with BrCa risk.
Results:
A previously identified co-purifying protein with PALB2 was identified, MRG15 (MORF4L1 gene). Results in human, mouse and C. elegans models delineate molecular and functional relationships with BRCA2, PALB2, RAD51 and RPA1 that suggest a role for MRG15 in the repair of DNA double-strand breaks. Mrg15-deficient murine embryonic fibroblasts showed moderate sensitivity to g-irradiation relative to controls and reduced formation of Rad51 nuclear foci. Examination of mutants of MRG15 and BRCA2 C. elegans orthologs revealed phenocopy by accumulation of RPA-1 (human RPA1) nuclear foci and aberrant chromosomal compactions in meiotic cells.
However, no alterations or mutations were identified for MRG15/MORF4L1 in unclassified FA patients and BrCa familial cases. Finally, no significant associations between common MORF4L1 variants and BrCa risk for BRCA1 or BRCA2 mutation carriers were identified: rs7164529, Ptrend = 0.45 and 0.05, P2df = 0.51 and 0.14, respectively; and rs10519219, Ptrend = 0.92 and 0.72, P2df = 0.76 and 0.07, respectively.
Conclusions:
While the present study expands on the role of MRG15 in the control of genomic stability, weak associations cannot be ruled out for potential low-penetrance variants at MORF4L1 and BrCa risk among BRCA2
mutation carriers.
KW - breast cancer
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-169119
VL - 13
IS - R40
ER -
TY - THES
A1 - Rost, Isabell
T1 - Gezielte Anreicherungs- und neue DNA-Sequenzierungsstrategien für die molekulare Analyse von Fanconi-Anämie-Genen
T1 - Targeted enrichment and novel DNA sequencing strategies for the molecular analysis of fanconi anemia genes
N2 - Fanconi-Anämie (FA) ist, mit Ausnahme von Mutationen in FANCR/RAD51, eine autosomal-rezessive oder X-chromosomal vererbte Krankheit, die sich durch eine ausgesprochene klinische als auch genetische Heterogenität auszeichnet. Neben einem fortschreitenden Knochenmarksversagen zählen zu den typischen Merkmalen eine Vielzahl an angeborenen Fehlbildungen, wie beispielsweise Radialstrahlanomalien, Minderwuchs oder Pigmentierungsstörungen. Zudem besteht für FA-Patienten ein überdurchschnittlich hohes Risiko bereits in jungen Jahren an akuter myeloischer Leukämie oder soliden Tumoren zu erkranken. Bislang konnten in 21 FA-Genen (FANCA, -B, -C, - D1, -D2, -E, -F, -G, -I, -J, -L, -M, -N, -O, -P, -Q, -R, -S, -T, -U oder -V) krankheitsverursachende Mutationen identifiziert werden, deren Proteinprodukte maßgeblich an der Aufrechterhaltung der Genomstabilität beteiligt sind und Komponenten des FA/BRCA-DNA-Reparaturweges darstellen. In der klassischen FA-Mutationsanalyse kommen meist Sanger-Sequenzierungen sowie MLPA- und Immunblot-Analysen zum Einsatz. Da im Wesentlichen keine Genotyp-Phänotyp-Korrelation besteht, gestaltet sich, gerade bei seltenen FA-Komplementationsgruppen, der Nachweis von krankheitsverursachenden Mutationen oftmals sehr zeit- und kostenintensiv. Während der letzten Jahre wurden verschiedene Strategien zur Anreicherung und Sequenzierung entwickelt, welche die parallele Sequenzanalyse einzelner ausgewählter Gene, ganzer Exome oder sogar des gesamten Genoms und somit eine kosten- und zeiteffiziente Mutationsanalyse ermöglichen. In der vorliegenden Arbeit wurden unterschiedliche Anreicherungsmethoden mit anschließender Hochdurchsatzsequenzierung auf ihre Anwendbarkeit in der molekulargenetischen FA-Diagnostik getestet, um klassische Mutationsanalyse-Methoden zu ergänzen oder möglicherweise sogar ganz ersetzen zu können.
Der erste Teil der Arbeit befasste sich mit der Etablierung eines FA-spezifischen Genpanels zur Genotypisierung von FA-Patienten. Nachdem die Methode zunächst anhand von FA-Patienten mit bekannten Mutationen optimiert werden musste, erwies sie sich als effizienter Ansatz zum Nachweis krankheitsverursachender Mutationen bei FA-Patienten unbekannter Komplementationsgruppe. Durch die FA-Panelanalyse konnten 37 von 47 unklassifizierten Patienten einer FA-Komplementationsgruppe zugeordnet werden, indem deren kausalen Mutationen bestimmt wurden. In einem weiteren Ansatz sollte die Anwendbarkeit eines kommerziellen Anreicherungspanels zur FA-Diagnostik untersucht werden. Auch hier konnte ein Großteil der krankheitsverursachenden Mutationen von fünf bekannten wie auch 13 nicht zugeordneten FA-Patienten detektiert und somit eine molekulargenetische Diagnose bei neun weiteren, zuvor unklassifizierten FA-Patienten, gestellt werden. Ferner wurden sechs ausgewählte Patienten, zusätzlich zur Panelanreicherung, per Exomanalyse untersucht. Zum einen konnten Mutationen in bekannten FA-Genen bestätigt oder neu identifiziert werden. Zum anderen wurden auch potentiell pathogene Mutationen in DNA-Reparaturgenen außerhalb des FA/BRCA-Signalweges bei zwei Patienten mit unbestätigter Verdachtsdiagnose FA verifiziert. So wurde bei mehreren Mitgliedern einer Familie mit unterschiedlichen Tumorerkrankungen eine zuvor unbeschriebene homozygote Nonsense-Mutation in der BER-Glykosylase NTHL1 nachgewiesen, für welche bislang erst zwei pathogene Mutationen als Auslöser eines neuen Krebssyndroms bekannt sind. Bei einem weiteren Patienten wurden compound-heterozygote Mutationen in RPA1 detektiert, ein Gen für das bislang noch kein Krankheitsbild bekannt ist. Mit Hilfe der drei verschiedenen Anreicherungsstrategien konnten insgesamt 47 von 60 unklassifizierten FA-Patienten 13 verschiedenen Komplementationsgruppen eindeutig zugeordnet werden. Es zeigte sich dabei ein breites Spektrum an neuen, bislang unbeschriebenen FA-Mutationen. Den größten Anteil an der Gesamtzahl der nachgewiesenen Mutationen hatten Spleißmutationen, die auf eine Auswirkung auf das kanonische Spleißmuster untersucht wurden, um einen pathogenen Effekt nachweisen zu können.
Weiterhin schloss die Arbeit die Charakterisierung einzelner FA-Patienten bzw. Komplementationsgruppen mit ein. Dazu zählen die seltenen Untergruppen FA-T und FA-Q, für die jeweils ein neuer Patient identifiziert werden konnte. Durch die funktionelle Charakterisierung der dritten jemals beschriebenen FA-Q-Patientin konnten Einblicke in das Zusammenspiel der Reparatur von DNA-Quervernetzungen und der Nukleotidexzisionsreparatur gewonnen und die phänotypische Variabilität von FA durch die subjektive als auch zelluläre UV-Sensitivität der Patientin ergänzt werden. Darüber hinaus konnte das Mutationsspektrum in FA-I sowie FA-D2 erweitert werden. Eine genauere Untersuchung der Pseudogenregionen von FANCD2 ermöglichte dabei die gezielte Mutationsanalyse des Gens.
Insgesamt konnten die Ergebnisse dieser Arbeit dazu beitragen, das Mutationsspektrum in FA zu erweitern und durch die Identifizierung und Charakterisierung einzelner Patienten neue Einblicke in verschiedene Komponenten des FA/BRCA-Signalweges zu erhalten. Es zeigte sich, dass neue DNA-Sequenzierungsstrategien in der FA-Diagnostik eingesetzt werden können, um eine effiziente Mutationsanalyse zu gewährleisten und klassische Methoden in Teilbereichen zu ersetzen.
N2 - Fanconi anemia (FA) is, with the exception of mutations in FANCR/RAD51, an autosomal recessive or X-linked inherited disease that is characterized by a remarkable clinical and genetic heterogeneity. In addition to progressive bone marrow failure, typical features include a multitude of developmental malformations, such as radial ray anomalies, growth retardation or cutaneous pigment displacement. Additionally, FA patients have a higher risk for developing acute myelogenous leukemia or solid tumors early in life. To date, pathogenic mutations have been identified in 21 FA genes (FANCA, -B, -C, - D1, -D2, -E, -F, -G, -I, -J, -L, -M, -N, -O, -P, -Q, -R, -S, -T, -U or -V) whose protein products are responsible for maintaining genomic integrity and constitute components of the FA/BRCA DNA repair pathway. Typical methods for FA mutation analysis comprise Sanger sequencing as well as MLPA and immunoblot analyses. As no definite genotype-phenotype correlation exists, pathogenic mutation detection in rare subgroups is often quite time-consuming and cost-intensive. Within the last few years, distinct strategies for both enrichment and sequencing of a subset of genes, whole exomes or even the whole genome have been developed that facilitate a cost-effective and time-saving mutation analysis. In the present work different target-enrichment strategies followed by high-throughput sequencing were tested for their applicability in molecular genetic diagnostics of FA in order to complement or even replace classic strategies for mutation analysis.
The first part of this work addressed the establishment of an FA-specific gene panel for genotyping FA patients. After optimizing this method by means of FA patients with known mutations, this proved to be an efficient approach for detecting pathogenic mutations in FA patients of unknown complementation groups. Due to FA gene panel analysis, 37 of 47 unclassified FA patients were assigned to a complementation group based on the identification of their causative mutations. In another approach, a commercial enrichment panel was tested for its application in FA diagnostics. Again, most pathogenic mutations of five classified and 13 unclassified FA patients were detected, enabling a molecular diagnosis for nine previously unclassified FA patients. Moreover, six selected patients were studied by exome analysis in addition to panel enrichment. This allowed for mutations in known FA complementation groups to be confirmed or newly identified. Additionally, potentially pathogenic variants in DNA-repair genes outside the FA/BRCA pathway were verified in two patients with an unconfirmed suspected diagnosis of FA. One previously undescribed homozygous nonsense mutation in the BER glycosylase NTHL1 was detected in several members of one family with various tumors. For this gene, only two distinct pathogenic mutations were previously described to cause a novel cancer syndrome. In another patient, compound heterozygous mutations in RPA1 were detected, a gene for which no disease pattern is yet known. By means of the three different enrichment strategies a total of 47 of 60 unclassified FA patients were definitely assigned to 13 diverse complementation groups. In this context, a broad spectrum of previously undescribed mutations was identified. The majority of all verified mutations were splice mutations that were examined for an effect on the canonical splicing pattern in order to verify a pathogenic effect.
Additionally, this work also included the characterization of individual FA patients and complementation groups, respectively. These include the rare subgroups FA-T and FA-Q, for each of which one new patient was identified. Functional characterization of the third ever described FA-Q patient allowed new insights into the interplay of DNA interstrand-crosslink and nucleotide excision repair and broadened the spectrum of phenotypic variability of FA by the subjective and cellular UV sensitivity of this patient. Furthermore, the mutation spectrum in both FA-I and FA-D2 was expanded. Here, a closer investigation of the pseudogene regions of FANCD2 facilitated a precise mutation screening of the gene.
Overall, the results of this work broadened the mutation spectrum of FA and allowed new insights into diverse components of the FA/BRCA pathway by identifying and characterizing individual patients. It became apparent that novel strategies for DNA sequencing can be applied in FA diagnostics to ensure an efficient mutation analysis, as well as to replace some parts of classical approaches.
KW - Fanconi-Anämie
KW - DNS-Reparatur
KW - Sequenzdaten
KW - Genpanel
KW - Next generation sequencing
KW - Mutationsanalyse
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151096
ER -
TY - THES
A1 - Haertle, Larissa
T1 - Gestationsdiabetes und fetale Programmierung: Epigenetische Untersuchungen mit verschiedenen Next Generation Sequencing Techniken
T1 - Gestational Diabetes Mellitus and fetal programming: Epigenetic investigations with different Next Generation Sequencing Techniques
N2 - Eine intrauterine Gestationsdiabetes (GDM) Exposition induziert in den betroffenen Nachkommen eine lebenslang erhöhte Prädisposition für metabolische und komplexe Erkrankungen. Die Krankheitssuszeptibilität wird dabei durch epigenetische Veränderungen vermittelt, die sich über die Regulation der Genaktivität auch auf das Expressionsniveau und den Phänotypen auswirken. Um neue Gene zu finden, die eine Rolle in der fetalen Programmierung spielen, wurden in dieser Arbeit genomweite Methylierungsmuster von Nabelschnurbluten (FCBs) aus GDM-Schwangerschaften und Kontrollen miteinander verglichen. Mit Illumina Infinium HumanMethylation 450K Arrays konnten signifikante Gruppenunterschiede für insgesamt 65 CpG-Stellen (52 davon genassoziiert) festgestellt werden, die multiplem Testen standhielten. Mittels Pyrosequenzierung wurden vier dieser Kandidaten-Loci (ATP5A1, MFAP4, PRKCH, SLC17A4), sowie ein Gen aus der Literatur (HIF3A) genauer untersucht und die Effekte erfolgreich validiert. Für das zugrundeliegende multivariate Regressionsmodell wurden die potenziellen Störfaktoren Gestationsalter, kindliches Geschlecht und mütterlicher BMI berücksichtigt. Der GDM-Effekt zeigte sich stärker in der insulinbehandelten Subgruppe (I-GDM) als in der diätisch behandelten (D GDM) und scheint insgesamt multifaktoriell bedingt zu sein, da viele Gene betroffen waren, jedoch alle mit einer vergleichsweise niedrigen Effekt-Größe. Zusätzlich konnten für den MEG3 Promotor, MEST und PEG3, drei von vier geprägten Genen, die mittels Deep Bisulfite Sequencings (DBS) analysiert wurden, ebenfalls signifikante Methylierungs-unterschiede zwischen der GDM- und Kontroll-Gruppe detektiert werden. Die identifizierten Gene stellen labile Zielregionen für die GDM-induzierte intrauterine Programmierung dar und können zukünftig nützliche Biomarker für Krankheitsdiagnosen und Prognosen sein. Mittels DBS können darüber hinaus Einzelmolekül-Analysen durchgeführt werden, für die in differentiell methylierten Regionen (DMRs) anhand eines informativen SNPs die parentale Allel-Herkunft bestimmt und bei der Berechnung von Epimutationsraten einbezogen werden kann. Epimutationen wurde als solche gewertet, wenn sie ein > 50 % abnormal (de)methyliertes Methylierungsprofil aufwiesen. Die DBS-Daten wurden mit zwei verschiedenen Sequenzierplattformen generiert (Roche GS Junior und Illumina MiSeq). Für Zweitere wurde ein eigenes, unabhängiges Library-Präparations-Protokoll entwickelt. In Nabelschnurblut, adultem Blut und Viszeralfett wurden für die paternal exprimierte MEST Promotor DMR und die maternal exprimierte MEG3 intergenic (IG) DMR hohe Epimutationsraten für das jeweils unmethylierte Allel detektiert. Die geprägten (methylierten) Allele wiesen dagegen nur niedrige Epimutationsraten auf. Da MEST und MEG3 invers geprägte Gene sind, war die Hypermethylierung des nicht geprägten Allels (HNA) demnach unabhängig von der parentalen Allel-Herkunft. Die HNA scheint außerdem erst nach der Fertilisation aufzutreten, da in Spermien nur sehr wenige Epimutationen gefunden wurden. Für die sekundäre MEG3 Promotor DMR (deren Prägung von der primären MEG3 IG-DMR reguliert wird) wurde ein deutlich schwächerer, wenngleich signifikanter HNA-Effekt im FCB gemessen, für die paternal exprimierte PEG3 Promotor DMR konnte dagegen kein signifikanter Unterschied zwischen den beiden parentalen Epimutationsraten festgestellt werden. Der HNA-Effekt für die MEST DMR, MEG3 IG-DMR und MEG3 Promotor DMR war weder mit GDM noch mit Adipositas assoziiert und zeigte allgemein eine große interindividuelle Varianz. Die Aufrechterhaltung differenzieller Methylierungsmuster in Imprinting Kontrollregionen (ICRs) scheint in manchen Entwicklungs-Zeitspannen von großer Bedeutung und damit streng kontrolliert zu sein, später jedoch redundant zu werden, was sich in der Anreicherung von stochastischen sowie umweltinduzierten Fehlern auf dem nicht geprägten Allel äußern kann. HNA-suszeptible geprägte Gene ähneln in mancherlei Hinsicht metastabilen Epiallelen. Diese Studie zeigt, dass sowohl stochastische Faktoren als auch Umweltstimuli während der frühen embryonalen Entwicklung u.a. über HNA-Effekte geprägte Gen-Netzwerke programmieren, die in Wachstumsprozesse involviert sind. Um tiefere Einblicke in allelspezifische Prägungsprofile zu erhalten, wären umfangreiche DBS HNA-Längsschnittstudien aller 50-100 human geprägten Gene in unterschiedlichen Gewebetypen und Differenzierungsstadien wünschenswert.
N2 - Intrauterine exposure to gestational diabetes mellitus (GDM) induces lifelong increased predisposition for metabolic and complex diseases in the exposed progeny. The elevated disease susceptibility is transmitted via epigenetic alterations that influence gene expression levels and phenotypes through regulation of gene activity. Genome-wide methylation profiles of fetal cord bloods (FCBs) were investigated in GDM and control pregnancies in order to identify new genes susceptible to fetal programming. After multiple testing correction, we found 65 significantly differentially methylated CpG sites between GDM and control groups (52 of which were gene associated) within the Illumina Infinium HumanMethylation 450K array data. Using pyrosequencing, we successfully confirmed the observed results in four of these candidate loci (ATP5A1, MFAP4, PRKCH, SLC17A4) and one gene from the literature (HIF3A). A multivariate regression model was adjusted for the confounding factors gestational age, fetal sex and maternal BMI. The GDM effect was stronger within the insulin treated subgroup (I-GDM) compared to the dietary subgroup (D GDM), suggesting that GDM is a multifactorial disease evidenced by changes of small effect size in multiple genes. Significant mean methylation differences were detected between the GDM group and controls in three out of four imprinted genes (MEG3 promoter, MEST and PEG3) that were analyzed with Deep Bisulfite Sequencing (DBS). The identified genes represent labile target regions for GDM-induced intrauterine programming and could represent future biomarkers for disease diagnosis and prognosis. Furthermore, DBS enables sequencing at a single allele resolution and the calculation of allele specific epimutation rates by differentiating the parental origin of alleles via an informative SNP within differentially methylated regions (DMRs). Epimutations were characterized as alleles showing > 50 % aberrantly (de)methylated CpG sites. DBS data were generated using two different sequencing platforms (Roche GS Junior and Illumina MiSeq). An independent library preparation protocol was established for Illumina MiSeq sequencing. The paternally expressed MEST promoter DMR and the maternally expressed MEG3 intergenic (IG) DMR showed high epimutation rates for the unmethylated alleles in FCB, as well as adult blood and visceral adipose tissue. On the contrary, only minor epimutation rates were displayed by the imprinted (methylated) alleles. Thus, hypermethylation of the non-imprinted allele (HNA) was independent of parental origin, as MEST and MEG3 are opposingly imprinted genes. Very low epimutation rates in sperm indicate that the HNA effect arises after fertilization. A weak but significant HNA was also found for the secondary MEG3 promoter DMR (which is known to be regulated by the MEG3 IG-DMR). The paternally expressed PEG3 promoter DMR showed no HNA and no difference in parental epimutation rates. The observed HNA effect (for the MEST DMR, the MEG3 IG-DMR and the MEG3 promoter DMR) was neither associated with GDM nor obesity and exhibited a large interindividual variance. Maintenance of differential methylation profiles in imprinting control regions (ICRs) seems to be of great importance during some developmental periods and is therefore strictly controlled in germ cells. Later on, it might become redundant manifested in the accumulation of stochastic as well as environmentally-induced errors on the non-imprinted allele. There is evidence that HNA-susceptible imprinted genes resemble metastable epialleles in many aspects. Therefore, we suggest that stochastic as well as environmental stimuli program imprinted gene networks that are important for growth related processes during early development using HNA. Further longitudinal studies of all 50 – 100 imprinted genes would benefit in a deeper insight in allele-specific imprinting patterns of various human tissues.
KW - Schwangerschaftsdiabetes
KW - Genetisches Imprinting
KW - Epigenetik
KW - Next Generation Sequencing (NGS)
KW - Fetale Programmierung
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-156465
ER -
TY - THES
A1 - Knies, Kerstin
T1 - Neue Fanconi-Anämie-Gene als Wächter des Genoms
T1 - New Fanconi anemia genes as guardians of the genome
N2 - Fanconi Anämie (FA) gehört zu den seltenen Chromsomeninstabilitäts-Syndromen. Ursächlich für die Erkrankung sind biallelische Mutationen mit autosomal rezessiver Vererbung in einem der bisher bekannten 21 Genen (FANCA, -B, -C, -D1, -D2, -E, -F, -G, -I, -J, -L, -M, -N, -O, -P, -Q, -R, -S, -T, -U und –V). Eine Ausnahme stellen FANCB und FANCS dar, die X-chromosomal rezessiv bzw. mit einem dominant negativen Effekt vererbt werden. Die Genprodukte sind als Teil des FA/BRCA-DNA-Reparatur Netzwerks bei der Beseitigung von DNA-Interstrang-Quervernetzungen (ICL) involviert. ICLs führen zu einer Stagnation der Replikationsgabel und blockieren somit wichtige zelluläre Prozesse wie Replikation und Transkription, sodass eine Aufrechterhaltung der Genomstabilität nicht mehr gewährleistet ist.
FA ist gekennzeichnet durch angeborene Fehlbildungen, fortschreitendes Knochenmarkversagen und eine erhöhte Prädisposition gegenüber Krebserkrankungen. Die Diagnose basiert auf phänotypischen Auffälligkeiten und wird auf zellulärer Ebene durch die Hypersensititvät gegenüber DNA-quervernetzenden Substanzen wie Mitomycin C (MMC) bestätigt. Da nicht jeder Patient einer bisher bekannten Komplementationsgruppe zugeordnet werden kann und herkömmliche molekulare Diagnostikverfahren mit der steigenden Anzahl an FA-Genen mühsam, zeitaufwändig und teuer geworden sind, war es nötig, neue molekulare Verfahren wie Whole Exome Sequencing (WES) zu etablieren. Im Rahmen dieser Arbeit wurde das Potential dieser Methode im Bezug auf die FA-Genotypisierung erforscht. Bei der Suche nach einer optimalen Anwendung des WES, untersuchten wir verschiedene Anreicherungs- und Sequenziertechniken. Dennoch führen Fehler in den Datenbanken sowie Pseudogene zu falschen Dateninterpretationen und –darstellungen und stellen somit eine Herausforderung dar. Trotzdem zeigen unserer Daten, dass WES eine wertvolle Methode in der Molekulardiagnostik von FA ist. Dies bestätigte sich durch die Zuordnung mehrerer, vorher unklassifizierter FA-Patienten zu den bekannten Komplementationsgruppen und der Ergänzung eines siebten Patienten zum Subtyp FA-P, im Rahmen von zwei Next Generation Sequencing (NGS) Publikationen.
Außerdem wurden mit Hilfe von WES zwei neue FA-Gene (FANCQ und FANCW) im Rahmen dieser Arbeit gefunden, wobei XPF (FANCQ) das erste Gen überhaupt war, welches anhand von NGS detektiert wurde. ERCC4/XPF ist eine strukturspezifische Endonuklease, die durch ein Gen kodiert wird, welches bereits vorher mit den Krankheiten Xeroderma Pigmentosum (XP) und dem segmentalen XFE progeroid Syndrom in Verbindung gebracht wurde. Unsere Daten zeigen, dass abhängig von der Mutation in XPF, Patienten eine der drei unterschiedlichen Funktionsstörungen aufweisen. Dies hebt die multifunktionale Stellung der XPF Endonuklease im Rahmen der Genomstabilität und von humanen Erkrankungen hervor. Das zweite Gen, das während dieser Arbeit entdeckt wurde, ist die WD40-Domäne tragende E3 Ubiquitin Ligase RFWD3, die kürzlich mit DNA Reparatur und insbesondere HR verknüpft wurde. Wir konnten zeigen, dass eine RFWD3 Mutation in der WD40-Domäne bei einem FA-Patienten mit der genetischen Erkrankung Fanconi Anämie assoziiert ist. Die HR ist in RFWD3 (FANCW) mutierten Zellen gestört, was auf einer verminderten Relokalisation von mutiertem RFWD3 an das Chromatin und einer defekten Interaktion mit RPA beruht. Des Weiteren weisen Rfwd3 defiziente Mäuse typische Merkmale anderer FA-Mausmodelle auf, wie verminderte Fertilität, ovarielle und testikuläre Atrophie sowie eine reduzierte Lebenserwartung.
Insgesamt zeigt diese Arbeit, dass neue molekulare Ansätze wie NGS ein wertvolles Hilfsmittel in der FA-Diagnostik sind um bisher unklassifizierte Patienten einer Komplementationsgruppe zuordnen zu können. Zudem konnten mit Hilfe dieser Technik zwei neue Gene identifiziert werden. Deren Charakterisierung trägt zu einer Vervollständigung und weiteren Aufklärung des FA/BRCA-DNA-Reparatur-Netzwerks bei.
N2 - Fanconi anemia (FA) is a rare genomic instability syndrome. Biallelic mutations are disease causing in any one of at least 21 genes (FANCA, -B, -C, -D1, -D2, -E, -F, -G, -I, -J, -L, -M, -N, -O, -P, -Q, -R, -S, -T, -U and -V). All are inherited in an autosomal recessive way, except FANCB and FANCS, which are inherited in a X-chromosomal recessive and a dominant negative way, respectively. The gene products are involved in the FA/BRCA DNA damage response pathway to remove interstrand-crosslinks (ICL). ICLs cause stalled replication forks and hence block crucial cellular processes like replication and transcription resulting in decreased maintenance of genome stability.
FA is characterized by congenital malformations, progressive bone marrow failure (BMF), and susceptibility to malignancies. Patients are diagnosed based upon phenotypical manifestations and the diagnosis of FA is confirmed by the hypersensitivity of cells to DNA interstrand crosslinking agents such as Mitomycin C (MMC). Since not every patient can be assigned to a complementation group and customary molecular diagnostics has become increasingly cumbersome, time-consuming and expensive the more FA genes have been identified new molecular approaches like Whole Exome Sequencing (WES) has been established. The potential of this method for FA genotyping has been investigated in the context of this thesis. By exploring different enrichment and sequencing techniques, we were able to identify the pathogenic mutations in each case using WES. However, database errors and pseudogenes pose challenges to interpret data correctly. Nevertheless our results show that WES is a valuable tool for molecular diagnosis of FA, since we were able to assign several previously unclassified FA patients to known complementation groups in the framework of two Next Generation Sequencing (NGS) studies.
In addition WES revealed two new FA-genes, XPF and RFWD3. Extraordinarily, XPF (FANCQ) is the first gene to be detected with NGS. ERCC4/XPF is a structure specific nuclease - encoding a gene previously connected to xeroderma pigmentosum (XP) and segmental XFE progeroid syndrome. Depending on the type of ERCC4 mutation individuals present with one of the three clinically distinct disorders highlighting the multifunctional nature of the XPF endonuclease in genome stability and human disease. The second gene identified within this thesis is the WD40-containing E3 ubiquitin ligase RFWD3, which has been recently linked to the repair of DNA damage by Homologous Recombination (HR). Here, we show that an RFWD3 mutation within the WD40 domain of a patient with typical FA malformations is connected to the genetic disease Fanconi anemia (FA). Disordered HR is the result of depleted relocation of mutant RFWD3 to chromatin and defective physical interaction with RPA. In addition, Rfwd3 knockout mice show ovarian and testicular atrophy, a reduced life span and pups with sub-Mendelian birth ratios indicating embryonal-lethality. These features resemble other FA mouse models.
In summary, this work showed that new molecular approaches like WES are valuable tools for FA diagnosis. Additionally, this method is a useful medium to assign FA patients to so far unknown complementation groups. Two novel genes have been identified and contribute to further completion of the FA/BRCA DNA repair network in the context of genome stability.
KW - DNA Reparatur
KW - Fanconi Anämie
KW - Neue Fanconi Anämie Gene
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150669
ER -
TY - THES
A1 - Maierhofer, Anna
T1 - Altersassoziierte und strahleninduzierte Veränderungen des genomweiten DNA-Methylierungs-Profils
T1 - Age-associated and radiation-induced changes in genome-wide DNA methylation
N2 - Der Prozess des Alterns ist ein komplexer multifaktorieller Vorgang, der durch eine sukzessive Verschlechterung der physiologischen Funktionen charakterisiert ist. Ein hohes Alter ist der Hauptrisikofaktor für die meisten Krankheiten, einschließlich Krebs und Herz-Kreislauf-Erkrankungen. Das Verständnis der epigenetischen Mechanismen, die in den Prozess des Alterns involviert sind, könnte zur Entwicklung pharmakologischer Interventionen beitragen, die nicht nur die Lebenserwartung erhöhen, sondern auch den Beginn des altersassoziierten funktionellen Abbaus verzögern könnten. Durch die Langzeit-Kultivierung primärer humaner Fibroblasten wurde ein in vitro Modell für das Altern etabliert, das die Identifizierung altersassoziierter DNA-Methylierungs-Veränderungen ermöglichte. Die in vitro Alterung konnte mit einer globalen Hypomethylierung und einer erhöhten DNA-Methylierung der ribosomalen DNA assoziiert werden. Darüber hinaus konnten DNA-Methylierungs-Veränderungen in Genen und Signalwegen, die für das Altern relevant sind, und ein erhöhtes epigenetisches Alter nachgewiesen werden.
Das in vitro Modell für das Altern wurde verwendet, um neben den direkten Effekten ionisierender Strahlung auf die DNA-Methylierung auch deren Langzeit-Effekte zu untersuchen. Die Strahlentherapie ist ein entscheidendes Element der Krebstherapie, hat aber auch negative Auswirkungen und kann unter anderem das Risiko für die Entwicklung eines Zweittumors erhöhen. Bei externer Bestrahlung wird neben dem Tumor auch gesundes Gewebe ionisierender Strahlung ausgesetzt. Daher ist es wichtig zu untersuchen, wie Zellen mit intakten DNA-Reparatur-Mechanismen und funktionierenden Zellzyklus-Checkpoints durch diese beeinflusst werden. In der frühen Phase der DNA-Schadensantwort auf Bestrahlung wurden in normalen Zellen keine wesentlichen DNA-Methylierungs-Veränderungen beobachtet. Mehrere Populations-Verdoppelungen nach Strahlenexposition konnten dagegen eine globale Hypomethylierung, eine erhöhte DNA-Methylierung der ribosomalen DNA und ein erhöhtes epigenetisches Alter detektiert werden. Des Weiteren zeigten Gene und Signalwege, die mit Krebs in Verbindung gebracht wurden, Veränderungen in der DNA-Methylierung. Als Langzeit-Effekte ionisierender Strahlung traten somit die mit der in vitro Alterung assoziierten DNA-Methylierungs-Veränderungen verstärkt auf und ein epigenetisches Muster, das stark an das DNA-Methylierungs-Profil von Tumorzellen erinnert, entstand. Man geht davon aus, dass Veränderungen der DNA-Methylierung eine aktive Rolle in der Entwicklung eines Tumors spielen. Die durch ionisierende Strahlung induzierten DNA-Methylierungs-Veränderungen in normalen Zellen könnten demnach in die Krebsentstehung nach Strahlenexposition involviert sein und zu dem sekundären Krebsrisiko nach Strahlentherapie beitragen. Es ist bekannt, dass Patienten unterschiedlich auf therapeutische Bestrahlung reagieren. Die Ergebnisse dieser Arbeit weisen darauf hin, dass die individuelle Sensitivität gegenüber ionisierender Strahlung auch auf epigenetischer Ebene beobachtet werden kann.
In einem zweiten Projekt wurden Gesamtblutproben von Patienten mit Werner-Syndrom, einer segmental progeroiden Erkrankung, und gesunden Kontrollen analysiert, um mit dem vorzeitigen Altern in Verbindung stehende DNA-Methylierungs-Veränderungen zu identifizieren. Werner-Syndrom konnte nicht mit einer globalen Hypomethylierung, jedoch mit einer erhöhten DNA-Methylierung der ribosomalen DNA und einem erhöhten epigenetischen Alter assoziiert werden. Das vorzeitige Altern geht demzufolge mit spezifischen epigenetischen Veränderungen einher, die eine Beschleunigung der mit dem normalen Altern auftretenden DNA-Methylierungs-Veränderungen darstellen.
Im Rahmen dieser Arbeit konnte die Bedeutung epigenetischer Mechanismen im Prozess des Alterns hervorgehoben werden und gezeigt werden, dass sowohl exogene Faktoren, wie ionisierende Strahlung, als auch endogene Faktoren, wie das in Werner-Syndrom-Patienten mutiert vorliegende WRN-Gen, altersassoziierte DNA-Methylierungs-Veränderungen beeinflussen können.
N2 - Aging is a complex, multifactorial process that is characterized by the successive deterioration of normal physiological functions. Age is the main risk factor for most diseases, including cancer. Understanding the epigenetic mechanisms that are involved in the aging process could contribute to the development of pharmacological interventions not only increasing lifespan but also delaying the onset of age-dependent functional decline. An in vitro model for aging was established by long-term culturing of primary human fibroblasts and used to identify age-associated changes in DNA methylation. In vitro aging could be linked to global hypomethylation, elevated DNA methylation of ribosomal DNA, a higher epigenetic age and alterations in DNA methylation of genes and pathways being relevant for aging.
The in vitro model for aging allowed to analyse the long-term effects of ionizing radiation on DNA methylation in addition to their direct effects. Radiotherapy is an important element of cancer treatment but can also have negative effects and increase the risk of second cancers. Although radiotherapy is targeted to the tumour, it also affects the surrounding healthy tissue. Therefore, it is important to analyse the impacts of ionizing radiation on normal cells with intact DNA repair and cell cycle checkpoints. The early phase of DNA damage response to radiation does not seem to include great changes in DNA methylation in normal cells. In contrast, several population doublings after radiation exposure, global hypomethylation and DNA methylation changes of genes and pathways being linked to tumorigenesis were detected. Furthermore, DNA methylation of ribosomal DNA and the epigenetic age were increased. Thus, as long-term effects of ionizing radiation the age-associated changes in DNA methylation were enhanced and an epigenetic pattern strongly resembling the DNA methylation profile of tumour cells was observed. It is assumed that alterations in DNA methylation are not only side effects of carcinogenesis but rather play an active role during this process. Radiation-induced changes in DNA methylation could thus be involved in tumour development and contribute to the secondary cancer risk after radiotherapy. It is well known that patients react differently to therapeutic radiation. The results of this study suggest that individual radiation sensitivity is also reflected on epigenetic level.
In a second project whole blood samples from patients with Werner syndrome, a segmental progeroid syndrome, and healthy controls were analysed to identify changes in DNA methylation associated with premature aging. Werner syndrome could not be linked to global hypomethylation, but to an increased epigenetic age and elevated methylation levels of ribosomal DNA. Hence, premature aging seems to be accompanied by specific alterations in DNA methylation representing an acceleration of the DNA methylation changes associated with normal aging.
This work outlines the importance of epigenetic mechanisms in the aging process and shows that not only exogenous factors like ionizing radiation but also endogenous factors like Werner syndrome causing mutations in the WRN gene can influence age-associated changes in DNA methylation.
KW - Methylierung
KW - Ionisierende Strahlung
KW - Altern
KW - Progeria adultorum
KW - Epigenetik
KW - Epigenetische Uhr
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-174134
ER -
TY - JOUR
A1 - Rodríguez-Mari, Adriana
A1 - Wilson, Catherine
A1 - Titus, Tom A.
A1 - Canestro, Cristian
A1 - BreMiller, Ruth A.
A1 - Yan, Yi-Lin
A1 - Nanda, Indrajit
A1 - Johnston, Adam
A1 - Kanki, John P.
A1 - Gray, Erin M.
A1 - He, Xinjun
A1 - Spitsbergen, Jan
A1 - Schindler, Detlev
A1 - Postlethwait, John H.
T1 - Roles of brca2 (fancd1) in Oocyte Nuclear Architecture, Gametogenesis, Gonad Tumors, and Genome Stability in Zebrafish
JF - PLoS Genetics
N2 - Functional near-infrared spectroscopy (fNIRS) is an established optical neuroimaging method for measuring functional hemodynamic responses to infer neural activation. However, the impact of individual anatomy on the sensitivity of fNIRS measuring hemodynamics within cortical gray matter is still unknown. By means of Monte Carlo simulations and structural MRI of 23 healthy subjects (mean age: (25.0 +/- 2.8) years), we characterized the individual distribution of tissue-specific NIR-light absorption underneath 24 prefrontal fNIRS channels. We, thereby, investigated the impact of scalp-cortex distance (SCD), frontal sinus volume as well as sulcal morphology on gray matter volumes (V(gray)) traversed by NIR-light, i.e. anatomy-dependent fNIRS sensitivity. The NIR-light absorption between optodes was distributed describing a rotational ellipsoid with a mean penetration depth of (23.6 +/- 0.7) mm considering the deepest 5% of light. Of the detected photon packages scalp and bone absorbed (96.4 +/- 9: 7)% and V(gray) absorbed (3.1 +/- 1.8)% of the energy. The mean V(gray) volume (1.1 +/- 0.4)cm(3) was negatively correlated (r = - .76) with the SCD and frontal sinus volume (r = - .57) and was reduced by 41.5% in subjects with relatively large compared to small frontal sinus. Head circumference was significantly positively correlated with the mean SCD (r = .46) and the traversed frontal sinus volume (r = .43). Sulcal morphology had no significant impact on V(gray). Our findings suggest to consider individual SCD and frontal sinus volume as anatomical factors impacting fNIRS sensitivity. Head circumference may represent a practical measure to partly control for these sources of error variance.
KW - oocytes
KW - zebrafish
KW - genetic causes of cancer
KW - testes
KW - apoptosis
KW - gonads
KW - sperm
KW - embryos
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-142285
VL - 7
IS - 3
ER -
TY - JOUR
A1 - Weis, Eva
A1 - Schoen, Holger
A1 - Victor, Anja
A1 - Spix, Claudia
A1 - Ludwig, Marco
A1 - Schneider-Raetzke, Brigitte
A1 - Kohlschmidt, Nicolai
A1 - Bartsch, Oliver
A1 - Gerhold-Ay, Aslihan
A1 - Boehm, Nils
A1 - Grus, Franz
A1 - Haaf, Thomas
A1 - Galetzka, Danuta
T1 - Reduced mRNA and Protein Expression of the Genomic Caretaker RAD9A in Primary Fibroblasts of Individuals with Childhood and Independent Second Cancer
JF - PLoS ONE
N2 - Background:
The etiology of secondary cancer in childhood cancer survivors is largely unclear. Exposure of normal somatic cells to radiation and/or chemotherapy can damage DNA and if not all DNA lesions are properly fixed, the mis-repair may lead to pathological consequences. It is plausible to assume that genetic differences, i.e. in the pathways responsible for cell cycle control and DNA repair, play a critical role in the development of secondary cancer.
Methodology/Findings:
To identify factors that may influence the susceptibility for second cancer formation, we recruited 20 individuals who survived a childhood malignancy and then developed a second cancer as well as 20 carefully matched control individuals with childhood malignancy but without a second cancer. By antibody microarrays, we screened primary fibroblasts of matched patients for differences in the amount of representative DNA repair-associated proteins. We found constitutively decreased levels of RAD9A and several other DNA repair proteins in two-cancer patients, compared to one-cancer patients. The RAD9A protein level increased in response to DNA damage, however to a lesser extent in the two-cancer patients. Quantification of mRNA expression by real-time RT PCR revealed lower RAD9A mRNA levels in both untreated and 1 Gy gamma-irradiated cells of two-cancer patients.
Conclusions/Significance:
Collectively, our results support the idea that modulation of RAD9A and other cell cycle arrest and DNA repair proteins contribute to the risk of developing a second malignancy in childhood cancer patients.
KW - DNA methylation
KW - Malignant neoplasms
KW - Genes
KW - Instability
KW - Stability
KW - Susceptibility
KW - Checkpoints
KW - Repair
KW - Damage
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-141838
VL - 6
IS - 10
ER -
TY - JOUR
A1 - Kuhtz, Juliane
A1 - Schneider, Eberhard
A1 - El Hajj, Nady
A1 - Zimmermann, Lena
A1 - Fust, Olga
A1 - Linek, Bartosz
A1 - Seufert, Rudolf
A1 - Hahn, Thomas
A1 - Schorsch, Martin
A1 - Haaf, Thomas
T1 - Epigenetic heterogeneity of developmentally important genes in human sperm: Implications for assisted reproduction outcome
JF - Epigenetics
N2 - The molecular basis of male infertility is poorly understood, the majority of cases remaining unsolved. The association of aberrant sperm DNA methylation patterns and compromised semen parameters suggests that disturbances in male germline epigenetic reprogramming contribute to this problem. So far there are only few data on the epigenetic heterogeneity of sperm within a given sample and how to select the best sperm for successful infertility treatment. Limiting dilution bisulfite sequencing of small pools of sperm from fertile donors did not reveal significant differences in the occurrence of abnormal methylation imprints between sperm with and without morphological abnormalities. Intracytoplasmic morphologically selected sperm injection was not associated with an improved epigenetic quality, compared to standard intracytoplasmatic sperm injection. Deep bisulfite sequencing (DBS) of 2 imprinted and 2 pluripotency genes in sperm from men attending a fertility center showed that in both samples with normozoospermia and oligoasthenoteratozoospermia (OAT) the vast majority of sperm alleles was normally (de)methylated and the percentage of epimutations (allele methylation errors) was generally low (<1%). However, DBS allowed one to identify and quantify these rare epimutations with high accuracy. Sperm samples not leading to a pregnancy, in particular in the OAT group, had significantly more epimutations in the paternally methylated GTL2 gene than samples leading to a live birth. All 13 normozoospermic and 13 OAT samples leading to a child had <1% GTL2 epimutations, whereas one (7%) of 14 normozoospermic and 7 (50%) of 14 OAT samples without pregnancy displayed 1–14% GTL2 epimutations.
KW - ART outcome
KW - deep bisulfite sequencing
KW - epigenetic heterogeneity
KW - GTL2
KW - sperm DNA methylation
KW - IMSI
KW - ICSI
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-150261
VL - 9
IS - 12
ER -
TY - THES
A1 - Mattern, Felix
T1 - Alterungsbedingte Effekte auf DNA-Methylierungsprofile entwicklungsrelevanter Gene in Eizellen und Embryonen am Modellorganismus Bos taurus
T1 - Aging-induced effects on DNA methylation profiles of developmental genes in oocytes and embryos on the model organism Bos taurus
N2 - Die postovulatorische Alterung sowie die ovarielle Alterung konnten bei der Anwendung assistierter Reproduktionstechniken (ARTs) als entscheidende Faktoren identifiziert werden, die den Reproduktionserfolg nachhaltig beeinträchtigen. Die postovulatorische Alterung tritt ein, sobald die reife Eizelle nicht mehr innerhalb ihres physiologischen Zeitfensters befruchtet wird. Die ovarielle Alterung beschreibt hingegen die Abnahme des Follikel-Vorrats mit zunehmendem Alter des weiblichen Individuums bzw. des Ovars. Sowohl die postovulatorische Alterung als auch die ovarielle Alterung führen u.a. zu einer reduzierten Oozytenqualität und einer geringeren Blastozystenrate. Die Zielsetzung dieser Arbeit bestand darin, den Einfluss der postovulatorischen Alterung und der ovariellen Alterung im Holstein-Rind (Bos taurus) auf die DNA-Methylierung entwicklungsrelevanter Gene in Eizellen und Embryonen zu untersuchen. Aus Schlachthof-Ovarien wurden Antralfollikeln unterschiedlicher Größe (<2 mm, 3-5 mm und >6 mm) isoliert. Eizellen aus Follikeln der Größe 3-5 mm wurden für 24h (physiologisch) und 48h (gealtert) in vitro gereift (IVM). Die gereiften Oozyten wurden anschließend in vitro fertilisiert und Embryonen im 4-6 Zellstadium generiert. Sowohl in den unreifen Eizellen aus Antralfollikeln unterschiedlicher Größe als auch in den gereiften Oozyten und den Embryonen wurde die Promotormethylierung der Gene bH19, bSNRPN, bZAR1, bDNMT3A, bOCT4, bDNMT3Lo und bDNMT3Ls analysiert. Zur Untersuchung der ovariellen Alterung wurden mittelgroßen Antralfollikel aus Ovarien lebender Rinder (in vivo) unterschiedlichen Alters (9-12 Monate, 3-7 Jahre und 8-11 Jahre) gewonnen. In den daraus isolierten unreifen Eizellen wurde die DNA-Methylierung der Promotorregionen der Gene bTERF2, bREC8, bBCL-XL, bPISD, bBUB1, bDNMT3Lo, bH19 und bSNRPN bestimmt. Als Methode zur Analyse der Promotormethylierung wurde die Limiting Dilution Bisulfit-Sequenzierung angewendet.
In unreifen Eizellen aus Antralfollikeln unterschiedlicher Größe (<2 mm, 3-5 mm und >6 mm) konnte ein erhöhtes Auftreten abnormal methylierter Allele in den geprägten Genen bH19 und bSNRPN von Eizellen kleiner Follikel (<2 mm) identifiziert werden. Dieses Ergebnis könnte eine mögliche Ursache einer bereits bekannten und mehrfach beschriebenen geringeren Entwicklungskompetenz von Eizellen kleiner Follikel (<2 mm) auf epigenetischer Ebene darstellen.
Die verlängerte Reifungsdauer der IVM-Eizellen hatte eine signifikante Hypermethylierung in der Promotorregion des Gens DNMT3Lo von 48h-gereiften Eizellen zur Folge. Beim Übergang von 48h-gereiften Eizellen zum Embryo konnte eine signifikante Hypomethylierung von CpG7 des stammzellspezifischen Transkripts DNMT3Ls beobachtet werden. Diese CpG-Stelle wies ebenfalls einen signifikanten Anstieg von CpGs mit nicht-eindeutigem Methylierungszustand in unreifen Eizellen mit steigender Follikelgröße auf. Da sich die CpG-Position innerhalb eines Sequenz-Motivs einer Bindungsstelle des Transkriptionsfaktors CREB befindet, könnten die Methylierungsdaten auf eine Interaktion zwischen dem Transkriptionsfaktor CREB und der DNA-Methylierung während der Entwicklung und Reifung der Eizelle sowie der Transition von der Eizelle zum Embryo hindeuten.
Die DNA-Methylierungsprofile der untersuchten Gene in unreifen Eizellen aus Kühen unterschiedlichen Alters (9-12 Monate, 3-7 Jahre und 8-11 Jahre) wiesen keine signifikanten Unterschiede zwischen den Altersgruppen auf. Die ovarielle Alterung bei Rindern zwischen 9 Monaten und 11 Jahren zeigte damit keinen Effekt auf die DNA-Methylierung der untersuchten Promotorregionen der Gene bTERF2, bREC8, bBCL-XL, bPISD, bBUB1, bDNMT3Lo, bH19 und bSNRPN.
Nach einer simulierten postovulatorischen Alterung durch eine in vitro Reifung für 48h konnte eine Veränderung der DNA-Methylierung der Oozyten-spezifischen (DNMT3Lo) und Stammzell-spezifischen (DNMT3Ls) Promotoren des katalytisch inaktiven Cofaktors von DNMT3A, DNMT3L, beobachtet werden. Die veränderte DNA-Methylierung von DNMT3Ls tritt dabei erst im frühen Embryo in Erscheinung und interagiert vermutlich mit dem Transkriptionsfaktor CREB. Die Veränderungen von DNMT3Lo in Eizellen und DNMT3Ls in den daraus generierten Embryonen lässt vermuten, dass es sich hierbei um eine dynamische Anpassung des Embryos auf äußere Umweltbedingungen der Eizelle über die Methylierung der DNA handelt.
N2 - Postovulatory aging and ovarian aging have been identified as key factors in assisted
reproductive techniques (ARTs) and have a lasting effect on reproductive success. Postovulatory
aging occurs if the mature egg is not fertilized within its physiological time window. On the other
hand, ovarian aging describes the decrease in the follicular reserve with increasing age of the
female or the ovary, respectively. Both post-ovulatory aging and ovarian aging result in reduced
oocyte quality and lower blastocyst rate. The aim of this thesis was to explore the effects of
postovulatory aging and ovarian aging in Holstein cattle (Bos taurus) on the DNA methylation of
developmentally important genes in oocytes and embryos. Antral follicles of different sizes (<2 mm,
3-5 mm and> 6 mm) were isolated from slaughterhouse ovaries. Female germ cells from middle-sized
follicles (3-5 mm) were matured for 24h (physiological conditions) and 48h (aged conditions) in
vitro (IVM). The IVM- oocytes were subsequently fertilized in vitro and embryos at the 4-6 cell
stage were generated. Promoter methylation of the genes bH19, bSNRPN, bZAR1, bDNMT3A, bOCT4,
bDNMT3Lo and bDNMT3Ls was analysed in immature oocytes from antral follicles of different sizes as
well as in matured oocytes and the respective embryos. For studying ovarian aging, middle-sized
antral follicles were obtained in vivo from animals of different age groups (9-12 months, 3-7 years
and 8-11 years). In the extracted immature gametes, the DNA methylation of the promoter regions of
bTERF2, bREC8, bBCL-XL, bPISD, bBUB1, bDNMT3Lo, bH19 and bSNRPN was examined. The limiting dilution
bisulfite (pyro)sequencing method was applied to determine the promoter methylation of the
candidate genes at the single allele level.
In immature oocytes from antral follicles of different diameters (<2 mm, 3-5 mm and> 6 mm) an
increased occurrence of abnormally methylated alleles of the imprinted genes bH19 and bSNRPN was
identified in small follicles (<2 mm). This failure to establish imprinting could be a possible
cause of a well-known reduced developmental potential of small follicles (<2 mm) at the epigenetic
level.
The extended maturation time of the IVM-oocytes resulted in a significant hypermethylation in the
promoter region of DNMT3Lo in 48h matured oocytes. After transition from 48h matured oocytes to
embryos, a significant hypomethylation of CpG7 of the stem cell specific transcript DNMT3Ls was
detected. The same CpG site showed a significant increase of CpGs with unclear methylation state in
immature female germ cells with increasing follicular size. This CpG position is located within a
potential binding site of the transcription factor CREB. Thus, the methylation data indicates an
interaction between the transcription factor CREB and the DNA methylation during development and
maturation of oocytes as well as during transition from the oocyte to the embryo.
The DNA methylation profiles of the analysed genes in immature oocytes from cows of different age
(9-12 months, 3-7 years and 8-11 years) showed no significant differences between age groups.
Hence, the ovarian aging in cattle between 9 months and 11 years caused no effect on the DNA
methylation of bTERF2, bREC8, bBCL-XL, bPISD, bBUB1, bDNMT3Lo, bH19 and bSNRPN.
After a simulated postovulatory aging by in vitro maturation for 48h, a change in the DNA
methylation of the oocyte-specific (DNMT3Lo) and stem cell-specific (DNMT3Ls) promoters of the
catalytically inactive DNA-methyltransferase DNMT3L was observed. The altered DNA methylation of
DNMT3Ls occurs in the early embryo and probably interacts with the transcription factor CREB. The
changes of DNMT3Lo in oocytes and DNMT3Ls in the resulting
embryos might represent a dynamic adaptation to external environmental conditions.
KW - Oozyte
KW - Epigenetik
KW - Altern
KW - DNS-Methyltransferase
KW - Ovarielle Alterung
KW - Postovulatorische Alterung
KW - Antralfollikel
KW - Holstein
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144562
ER -
TY - JOUR
A1 - Blanco, Ignacio
A1 - Kuchenbaecker, Karoline
A1 - Cuadras, Daniel
A1 - Wang, Xianshu
A1 - Barrowdale, Daniel
A1 - Ruiz de Garibay, Gorka
A1 - Librado, Pablo
A1 - Sanchez-Gracia, Alejandro
A1 - Rozas, Julio
A1 - Bonifaci, Núria
A1 - McGuffog, Lesley
A1 - Pankratz, Vernon S.
A1 - Islam, Abul
A1 - Mateo, Francesca
A1 - Berenguer, Antoni
A1 - Petit, Anna
A1 - Català, Isabel
A1 - Brunet, Joan
A1 - Feliubadaló, Lidia
A1 - Tornero, Eva
A1 - Benítez, Javier
A1 - Osorio, Ana
A1 - Ramón y Cajal, Teresa
A1 - Nevanlinna, Heli
A1 - Aittomäki, Kristina
A1 - Arun, Banu K.
A1 - Toland, Amanda E.
A1 - Karlan, Beth Y.
A1 - Walsh, Christine
A1 - Lester, Jenny
A1 - Greene, Mark H.
A1 - Mai, Phuong L.
A1 - Nussbaum, Robert L.
A1 - Andrulis, Irene L.
A1 - Domchek, Susan M.
A1 - Nathanson, Katherine L.
A1 - Rebbeck, Timothy R.
A1 - Barkardottir, Rosa B.
A1 - Jakubowska, Anna
A1 - Lubinski, Jan
A1 - Durda, Katarzyna
A1 - Jaworska-Bieniek, Katarzyna
A1 - Claes, Kathleen
A1 - Van Maerken, Tom
A1 - Díez, Orland
A1 - Hansen, Thomas V.
A1 - Jønson, Lars
A1 - Gerdes, Anne-Marie
A1 - Ejlertsen, Bent
A1 - De la Hoya, Miguel
A1 - Caldés, Trinidad
A1 - Dunning, Alison M.
A1 - Oliver, Clare
A1 - Fineberg, Elena
A1 - Cook, Margaret
A1 - Peock, Susan
A1 - McCann, Emma
A1 - Murray, Alex
A1 - Jacobs, Chris
A1 - Pichert, Gabriella
A1 - Lalloo, Fiona
A1 - Chu, Carol
A1 - Dorkins, Huw
A1 - Paterson, Joan
A1 - Ong, Kai-Ren
A1 - Teixeira, Manuel R.
A1 - Hogervorst, Frans B. L.
A1 - Van der Hout, Annemarie H.
A1 - Seynaeve, Caroline
A1 - Van der Luijt, Rob B.
A1 - Ligtenberg, Marjolijn J. L.
A1 - Devilee, Peter
A1 - Wijnen, Juul T.
A1 - Rookus, Matti A.
A1 - Meijers-Heijboer, Hanne E. J.
A1 - Blok, Marinus J.
A1 - Van den Ouweland, Ans M. W.
A1 - Aalfs, Cora M.
A1 - Rodriguez, Gustavo C.
A1 - Phillips, Kelly-Anne A.
A1 - Piedmonte, Marion
A1 - Nerenstone, Stacy R.
A1 - Bae-Jump, Victoria L.
A1 - O'Malley, David M.
A1 - Schmutzler, Rita K.
A1 - Wappenschmidt, Barbara
A1 - Rhiem, Kerstin
A1 - Engel, Christoph
A1 - Meindl, Alfons
A1 - Ditsch, Nina
A1 - Arnold, Norbert
A1 - Plendl, Hansjoerg J.
A1 - Niederacher, Dieter
A1 - Sutter, Christian
A1 - Wang-Gohrke, Shan
A1 - Steinemann, Doris
A1 - Preisler-Adams, Sabine
A1 - Kast, Karin
A1 - Varon-Mateeva, Raymonda
A1 - Gehrig, Andrea
A1 - Bojesen, Anders
A1 - Pedersen, Inge Sokilde
A1 - Sunde, Lone
A1 - Birk Jensen, Uffe
A1 - Thomassen, Mads
A1 - Kruse, Torben A.
A1 - Foretova, Lenka
A1 - Peterlongo, Paolo
A1 - Bernard, Loris
A1 - Peissel, Bernard
A1 - Scuvera, Giulietta
A1 - Manoukian, Siranoush
A1 - Radice, Paolo
A1 - Ottini, Laura
A1 - Montagna, Marco
A1 - Agata, Simona
A1 - Maugard, Christine
A1 - Simard, Jacques
A1 - Soucy, Penny
A1 - Berger, Andreas
A1 - Fink-Retter, Anneliese
A1 - Singer, Christian F.
A1 - Rappaport, Christine
A1 - Geschwantler-Kaulich, Daphne
A1 - Tea, Muy-Kheng
A1 - Pfeiler, Georg
A1 - John, Esther M.
A1 - Miron, Alex
A1 - Neuhausen, Susan L.
A1 - Terry, Mary Beth
A1 - Chung, Wendy K.
A1 - Daly, Mary B.
A1 - Goldgar, David E.
A1 - Janavicius, Ramunas
A1 - Dorfling, Cecilia M.
A1 - Van Rensburg, Elisabeth J.
A1 - Fostira, Florentia
A1 - Konstantopoulou, Irene
A1 - Garber, Judy
A1 - Godwin, Andrew K.
A1 - Olah, Edith
A1 - Narod, Steven A.
A1 - Rennert, Gad
A1 - Paluch, Shani Shimon
A1 - Laitman, Yael
A1 - Friedman, Eitan
A1 - Liljegren, Annelie
A1 - Rantala, Johanna
A1 - Stenmark-Askmalm, Marie
A1 - Loman, Niklas
A1 - Imyanitov, Evgeny N.
A1 - Hamann, Ute
A1 - Spurdle, Amanda B.
A1 - Healey, Sue
A1 - Weitzel, Jeffrey N.
A1 - Herzog, Josef
A1 - Margileth, David
A1 - Gorrini, Chiara
A1 - Esteller, Manel
A1 - Gómez, Antonio
A1 - Sayols, Sergi
A1 - Vidal, Enrique
A1 - Heyn, Holger
A1 - Stoppa-Lyonnet, Dominique
A1 - Léoné, Melanie
A1 - Barjhoux, Laure
A1 - Fassy-Colcombet, Marion
A1 - Pauw, Antoine de
A1 - Lasset, Christine
A1 - Fert Ferrer, Sandra
A1 - Castera, Laurent
A1 - Berthet, Pascaline
A1 - Cornelis, François
A1 - Bignon, Yves-Jean
A1 - Damiola, Francesca
A1 - Mazoyer, Sylvie
A1 - Sinilnikova, Olga M.
A1 - Maxwell, Christopher A.
A1 - Vijai, Joseph
A1 - Robson, Mark
A1 - Kauff, Noah
A1 - Corines, Marina J.
A1 - Villano, Danylko
A1 - Cunningham, Julie
A1 - Lee, Adam
A1 - Lindor, Noralane
A1 - Lázaro, Conxi
A1 - Easton, Douglas F.
A1 - Offit, Kenneth
A1 - Chenevix-Trench, Georgia
A1 - Couch, Fergus J.
A1 - Antoniou, Antonis C.
A1 - Pujana, Miguel Angel
T1 - Assessing associations between the AURKA-HMMR-TPX2-TUBG1 functional module and breast cancer risk in BRCA1/2 mutation carriers
JF - PLoS ONE
N2 - While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk of breast cancer in BRCA1 or BRCA2 mutation carriers. Forty-one single nucleotide polymorphisms (SNPs) were genotyped in 15,252 BRCA1 and 8,211 BRCA2 mutation carriers and subsequently analyzed using a retrospective likelihood approach. The association of HMMR rs299290 with breast cancer risk in BRCA1 mutation carriers was confirmed: per-allele hazard ratio (HR) = 1.10, 95% confidence interval (CI) 1.04 - 1.15, p = 1.9 x 10\(^{-4}\) (false discovery rate (FDR)-adjusted p = 0.043). Variation in CSTF1, located next to AURKA, was also found to be associated with breast cancer risk in BRCA2 mutation carriers: rs2426618 per-allele HR = 1.10, 95% CI 1.03 - 1.16, p = 0.005 (FDR-adjusted p = 0.045). Assessment of pairwise interactions provided suggestions (FDR-adjusted p\(_{interaction}\) values > 0.05) for deviations from the multiplicative model for rs299290 and CSTF1 rs6064391, and rs299290 and TUBG1 rs11649877 in both BRCA1 and BRCA2 mutation carriers. Following these suggestions, the expression of HMMR and AURKA or TUBG1 in sporadic breast tumors was found to potentially interact, influencing patients' survival. Together, the results of this study support the hypothesis of a causative link between altered function of AURKA-HMMR-TPX2-TUBG1 and breast carcinogenesis in BRCA1/2 mutation carriers.
KW - genetic interaction networks
KW - genome-wide association
KW - expression signature
KW - susceptibility loci
KW - survival
KW - modifiers
KW - polymorphism
KW - cell
KW - chip-seq
KW - elements
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143469
VL - 10
IS - 4
ER -
TY - JOUR
A1 - Schneider, Eberhard
A1 - Dittrich, Marcus
A1 - Böck, Julia
A1 - Nanda, Indrajit
A1 - Müller, Tobias
A1 - Seidmann, Larissa
A1 - Tralau, Tim
A1 - Galetzka, Danuta
A1 - El Hajj, Nady
A1 - Haaf, Thomas
T1 - CpG sites with continuously increasing or decreasing methylation from early to late human fetal brain development
JF - Gene
N2 - Normal human brain development is dependent on highly dynamic epigenetic processes for spatial and temporal gene regulation. Recent work identified wide-spread changes in DNA methylation during fetal brain development. We profiled CpG methylation in frontal cortex of 27 fetuses from gestational weeks 12-42, using Illumina 450K methylation arrays. Sites showing genome-wide significant correlation with gestational age were compared to a publicly available data set from gestational weeks 3-26. Altogether, we identified 2016 matching developmentally regulated differentially methylated positions (m-dDMPs): 1767 m-dDMPs were hypermethylated and 1149 hypomethylated during fetal development. M-dDMPs are underrepresented in CpG islands and gene promoters, and enriched in gene bodies. They appear to cluster in certain chromosome regions. M-dDMPs are significantly enriched in autism-associated genes and CpGs. Our results promote the idea that reduced methylation dynamics during fetal brain development may predispose to autism. In addition, m-dDMPs are enriched in genes with human-specific brain expression patterns and/or histone modifications. Collectively, we defined a subset of dDMPs exhibiting constant methylation changes from early to late pregnancy. The same epigenetic mechanisms involving methylation changes in cis-regulatory regions may have been adopted for human brain evolution and ontogeny.
KW - Autism spectrum disorders
KW - DNA methylation
KW - Genome
KW - Autism
KW - Frontal cortex
KW - Human prefrontal cortex
KW - Gene-expression
KW - Schizophrenia
KW - Patterns
KW - Transcription
KW - Epigenetics
KW - Environment
KW - Fetal brain development
KW - DNA methylation dynamics
KW - Methylome
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186936
VL - 592
IS - 1
ER -
TY - JOUR
A1 - Vigorito, Elena
A1 - Kuchenbaecker, Karoline B.
A1 - Beesley, Jonathan
A1 - Adlard, Julian
A1 - Agnarsson, Bjarni A.
A1 - Andrulis, Irene L.
A1 - Arun, Banu K.
A1 - Barjhoux, Laure
A1 - Belotti, Muriel
A1 - Benitez, Javier
A1 - Berger, Andreas
A1 - Bojesen, Anders
A1 - Bonanni, Bernardo
A1 - Brewer, Carole
A1 - Caldes, Trinidad
A1 - Caligo, Maria A.
A1 - Campbell, Ian
A1 - Chan, Salina B.
A1 - Claes, Kathleen B. M.
A1 - Cohn, David E.
A1 - Cook, Jackie
A1 - Daly, Mary B.
A1 - Damiola, Francesca
A1 - Davidson, Rosemarie
A1 - de Pauw, Antoine
A1 - Delnatte, Capucine
A1 - Diez, Orland
A1 - Domchek, Susan M.
A1 - Dumont, Martine
A1 - Durda, Katarzyna
A1 - Dworniczak, Bernd
A1 - Easton, Douglas F.
A1 - Eccles, Diana
A1 - Ardnor, Christina Edwinsdotter
A1 - Eeles, Ros
A1 - Ejlertsen, Bent
A1 - Ellis, Steve
A1 - Evans, D. Gareth
A1 - Feliubadalo, Lidia
A1 - Fostira, Florentia
A1 - Foulkes, William D.
A1 - Friedman, Eitan
A1 - Frost, Debra
A1 - Gaddam, Pragna
A1 - Ganz, Patricia A.
A1 - Garber, Judy
A1 - Garcia-Barberan, Vanesa
A1 - Gauthier-Villars, Marion
A1 - Gehrig, Andrea
A1 - Gerdes, Anne-Marie
A1 - Giraud, Sophie
A1 - Godwin, Andrew K.
A1 - Goldgar, David E.
A1 - Hake, Christopher R.
A1 - Hansen, Thomas V. O.
A1 - Healey, Sue
A1 - Hodgson, Shirley
A1 - Hogervorst, Frans B. L.
A1 - Houdayer, Claude
A1 - Hulick, Peter J.
A1 - Imyanitov, Evgeny N.
A1 - Isaacs, Claudine
A1 - Izatt, Louise
A1 - Izquierdo, Angel
A1 - Jacobs, Lauren
A1 - Jakubowska, Anna
A1 - Janavicius, Ramunas
A1 - Jaworska-Bieniek, Katarzyna
A1 - Jensen, Uffe Birk
A1 - John, Esther M.
A1 - Vijai, Joseph
A1 - Karlan, Beth Y.
A1 - Kast, Karin
A1 - Khan, Sofia
A1 - Kwong, Ava
A1 - Laitman, Yael
A1 - Lester, Jenny
A1 - Lesueur, Fabienne
A1 - Liljegren, Annelie
A1 - Lubinski, Jan
A1 - Mai, Phuong L.
A1 - Manoukian, Siranoush
A1 - Mazoyer, Sylvie
A1 - Meindl, Alfons
A1 - Mensenkamp, Arjen R.
A1 - Montagna, Marco
A1 - Nathanson, Katherine L.
A1 - Neuhausen, Susan L.
A1 - Nevanlinna, Heli
A1 - Niederacher, Dieter
A1 - Olah, Edith
A1 - Olopade, Olufunmilayo I.
A1 - Ong, Kai-ren
A1 - Osorio, Ana
A1 - Park, Sue Kyung
A1 - Paulsson-Karlsson, Ylva
A1 - Pedersen, Inge Sokilde
A1 - Peissel, Bernard
A1 - Peterlongo, Paolo
A1 - Pfeiler, Georg
A1 - Phelan, Catherine M.
A1 - Piedmonte, Marion
A1 - Poppe, Bruce
A1 - Pujana, Miquel Angel
A1 - Radice, Paolo
A1 - Rennert, Gad
A1 - Rodriguez, Gustavo C.
A1 - Rookus, Matti A.
A1 - Ross, Eric A.
A1 - Schmutzler, Rita Katharina
A1 - Simard, Jacques
A1 - Singer, Christian F.
A1 - Slavin, Thomas P.
A1 - Soucy, Penny
A1 - Southey, Melissa
A1 - Steinemann, Doris
A1 - Stoppa-Lyonnet, Dominique
A1 - Sukiennicki, Grzegorz
A1 - Sutter, Christian
A1 - Szabo, Csilla I.
A1 - Tea, Muy-Kheng
A1 - Teixeira, Manuel R.
A1 - Teo, Soo-Hwang
A1 - Terry, Mary Beth
A1 - Thomassen, Mads
A1 - Tibiletti, Maria Grazia
A1 - Tihomirova, Laima
A1 - Tognazzo, Silvia
A1 - van Rensburg, Elizabeth J.
A1 - Varesco, Liliana
A1 - Varon-Mateeva, Raymonda
A1 - Vratimos, Athanassios
A1 - Weitzel, Jeffrey N.
A1 - McGuffog, Lesley
A1 - Kirk, Judy
A1 - Toland, Amanda Ewart
A1 - Hamann, Ute
A1 - Lindor, Noralane
A1 - Ramus, Susan J.
A1 - Greene, Mark H.
A1 - Couch, Fergus J.
A1 - Offit, Kenneth
A1 - Pharoah, Paul D. P.
A1 - Chenevix-Trench, Georgia
A1 - Antoniou, Antonis C.
T1 - Fine-Scale Mapping at 9p22.2 Identifies Candidate Causal Variants That Modify Ovarian Cancer Risk in BRCA1 and BRCA2 Mutation Carriers
JF - PLoS ONE
N2 - Population-based genome wide association studies have identified a locus at 9p22.2 associated with ovarian cancer risk, which also modifies ovarian cancer risk in BRCA1 and BRCA2 mutation carriers. We conducted fine-scale mapping at 9p22.2 to identify potential causal variants in BRCA1 and BRCA2 mutation carriers. Genotype data were available for 15,252 (2,462 ovarian cancer cases) BRCA1 and 8,211 (631 ovarian cancer cases) BRCA2 mutation carriers. Following genotype imputation, ovarian cancer associations were assessed for 4,873 and 5,020 SNPs in BRCA1 and BRCA 2 mutation carriers respectively, within a retrospective cohort analytical framework. In BRCA1 mutation carriers one set of eight correlated candidate causal variants for ovarian cancer risk modification was identified (top SNP rs10124837, HR: 0.73, 95%CI: 0.68 to 0.79, p-value 2× 10−16). These variants were located up to 20 kb upstream of BNC2. In BRCA2 mutation carriers one region, up to 45 kb upstream of BNC2, and containing 100 correlated SNPs was identified as candidate causal (top SNP rs62543585, HR: 0.69, 95%CI: 0.59 to 0.80, p-value 1.0 × 10−6). The candidate causal in BRCA1 mutation carriers did not include the strongest associated variant at this locus in the general population. In sum, we identified a set of candidate causal variants in a region that encompasses the BNC2 transcription start site. The ovarian cancer association at 9p22.2 may be mediated by different variants in BRCA1 mutation carriers and in the general population. Thus, potentially different mechanisms may underlie ovarian cancer risk for mutation carriers and the general population.
KW - fine-scale mapping
KW - ovarian cancer
KW - genetics
KW - BRCA1
KW - BRCA2
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166869
VL - 11
IS - 7
ER -
TY - THES
A1 - Flunkert, Julia
T1 - Analyse genetischer Stabilität in den Nachkommen bestrahlter Zellen mittels klassischer Chromosomenbänderung und verschiedener Hochdurchsatz-Techniken
T1 - Analysis of genetic stability in the clonal descendants of irradiated cells using conventional chromosome banding and various high-throughput methods
N2 - Ionisierende Strahlung (IR) ist in der medizinischen Diagnostik und in der Tumortherapie von zentraler Bedeutung, kann aber Genominstabilität und Krebs auslösen. Strahleninduzierte Genominstabilität (RIGI) ist in den klonalen Nachkommen bestrahlter Zellen zu beobachten, die zugrundeliegenden Mechanismen sind jedoch noch unverstanden. Zur Erforschung von verzögerten Strahleneffekten wurden primäre embryonale Fibroblastenkulturen mit 2 Gray bestrahlt und für 20 Populationsverdopplungen klonal expandiert. Zellen, die keiner Strahlung ausgesetzt waren, dienten als Kontrolle für normale Alterungsprozesse. Die Klone wurden durch klassische Chromosomenbänderungstechniken analysiert und in Abhängigkeit der Stabilität ihres Genoms in Gruppen eingeteilt. Ein Klon wurde als stabil gewertet, wenn die analysierten Metaphasen keinerlei Auffälligkeiten zeigten, während instabile Klone ein Mosaik aus normalen und abnormalen Metaphasen waren. Die Zellen von zwei Spendern wurden untersucht, um interindividuelle Strahleneffekte zu beurteilen. Nach Bestrahlung hatten mehr als die Hälfte der Klone Metaphasen mit strukturellen Aberrationen und wurden dementsprechend als instabil eingestuft. Drei Klone zeigten zudem numerische Aberrationen, die ausschließlich das Y Chromosom betrafen. Fluoreszenz in situ Hybridisierungen verifizierten diese Beobachtung in weiteren Klonen und deuteten an, dass der Verlust des Y Chromosoms mit RIGI assoziiert ist.
Molekulare Karyotypisierungen mit SNP Arrays ergaben, dass IR in den Klonen Veränderungen der Kopienzahl auslöst. Ein Unterschied zwischen chromosomal stabilen und instabilen Klonen konnte jedoch nicht detektiert werden. Chromosomale Regionen, in denen sich bekanntermaßen fragile Stellen befinden, zeigten eine Anhäufung von CNVs. Ein RIGI Effekt konnte für die fragile Stelle 3B, in der sich das Gen FHIT befindet, identifiziert werden.
Exom Sequenzierungen von Klonen und der entsprechenden Massenkultur zeigten eine alterungsassoziierte Entstehung von Varianten. Der Effekt wurde durch die Einwirkung von Strahlung erhöht. Auf Ebene von einzelnen Nukleotiden konnten ebenfalls Anhäufungen von Schäden in bestimmten genomischen Bereichen detektiert werden, dieser Effekt ging ohne die typischen RIGI Endpunkte einher.
Die Ergebnisse der vorliegenden Arbeit zeigen, dass strahlenbedingte Veränderungen auf verschiedenen Ebenen (Chromosomen, Genkopienzahl und einzelnen Nukleotiden) beobachtet werden können, welche, unabhängig von RIGI, die Tumorentstehung begünstigen. Speziell Veränderungen im FRA3B Lokus und der Verlust des Y Chromosoms scheinen jedoch über die Destabilisierung des Genoms zur Krebsentstehung beizutragen.
N2 - Ionizing radiation is important in medical diagnosis and cancer treatment but can lead to genomic instability and secondary malignancies as a late effect. Radiation induced genomic instability (RIGI) can be observed in the progeny of irradiated cells but the underlying cellular processes remain to be elucidated. To study delayed genetic radiation effects, single cell fibroblast clones from two different male donors were established after a single X ray dose of 2 Gray. Non irradiated cells were used as controls to account for aging related effects. Clones were characterized using chromosome banding analysis. Stable clones were endowed with no karyotype abnormalities in all analysed metaphases after 20 Population doublings, whereas unstable clones showed both normal and abnormal metaphases. Two fibroblast strains were used to detect differences in radiation sensitivity. More than half of the irradiated clones were chromosomally abnormal and thus classified as unstable. Both banding analysis and fluorescence in situ hybridization revealed an increased rate of Y chromosome loss in irradiated clones which might be associated with RIGI.
Using SNP Arrays, an increased rate of de novo copy number variations (CNVs) was detected in the progeny of irradiated cells when compared to non irradiated controls. However, a significant difference between chromosomally stable and unstable clones was not found. CNVs clustered in chromosomal regions that are associated with known fragile sites. The fragile site 3B, which encompasses the gene FHIT, was found to be affected by CNVs in unstable clones suggesting a RIGI related effect.
Exome sequencing of clones and the respective primary cultures revealed an increased rate of variants during in vitro aging. This effect was further increased by radiation exposure. Analysis of single nucleotides showed a RIGI independent accumulation of damage in specific regions.
The results of the present study show that radiation induced changes can manifest as chromosomal abnormalities, copy number variations and DNA sequence mutations promoting tumorigenesis independent from RIGI. However, changes in FRA3B and loss of Y chromosome might trigger cancer through destabilizing the genome.
KW - Ionisierende Strahlung
KW - High throughput screening
KW - Instabilität
KW - Strahleninduzierte Genominstabilität
KW - Genom
KW - Genetik
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173670
ER -
TY - THES
A1 - Kühl, Julia
T1 - FAAP100, der FA/BRCA-Signalweg für genomische Stabilität und das DNA-Reparatur-Netzwerk
T1 - FAAP100, the FA/BRCA pathway for genomic stability and the DNA repair network
N2 - Die Fanconi-Anämie (FA) ist eine seltene, heterogene Erbkrankheit. Sie weist ein sehr variables klinisches Erscheinungsbild auf, das sich aus angeborenen Fehlbildungen, hämatologischen Funktionsstörungen, einem erhöhten Risiko für Tumorentwicklung und endokrinen Pathologien zusammensetzt. Die Erkrankung zählt zu den genomischen Instabilitätssyndromen, welche durch eine fehlerhafte DNA-Schadensreparatur gekennzeichnet sind. Bei der FA zeigt sich dies vor allem in einer charakteristischen Hypersensitivität gegenüber DNA-quervernetzenden Substanzen (z. B. Mitomycin C, Cisplatin). Der zelluläre FA-Phänotyp zeichnet sich durch eine erhöhte Chromosomenbrüchigkeit und einen Zellzyklusarrest in der G2-Phase aus. Diese Charakteristika sind bereits spontan vorhanden und werden durch Induktion mit DNA-quervernetzenden Substanzen verstärkt. Der Gendefekt ist dabei in einem der 22 bekannten FA-Gene (FANCA, -B, -C, -D1, -D2, -E, -F, -G, -I, -J, -L, -M, -N, -O, -P, -Q, -R, -S, -T, -U, -V, -W) oder in noch unbekannten FA-Genen zu finden. Die FA-Gendefekte werden mit Ausnahme von FANCR (dominant-negative de novo Mutationen) und FANCB (X-chromosomal) autosomal rezessiv vererbt. Die FA-Genprodukte bilden zusammen mit weiteren Proteinen den FA/BRCA-Signalweg. Das Schlüsselereignis dieses Signalwegs stellt die Monoubiquitinierung von FANCD2 und FANCI (ID2-Komplex) dar. Ausgehend davon lässt sich zwischen upstream- und downstream-gelegenen FA-Proteinen unterscheiden. Letztere sind direkt an der DNA-Schadensreparatur beteiligt. Zu den upstream-gelegenen Proteinen zählt der FA-Kernkomplex, der sich aus bekannten FA-Proteinen und aus FA-assoziierten-Proteinen (FAAPs) zusammensetzt und für die Monoubiquitinierung des ID2-Komplexes verantwortlich ist. Für FAAPs wurden bisher keine pathogenen humanen Mutationen beschrieben. Zu diesen Proteinen gehört auch FAAP100, das mit FANCB und FANCL innerhalb des FA-Kernkomplexes den Subkomplex LBP100 bildet.
Durch die vorliegende Arbeit wurde eine nähere Charakterisierung dieses Proteins erreicht. In einer Amnion-Zelllinie konnte eine homozygote Missense-Mutation identifiziert werden. Der Fetus zeigte einen typischen FA-Phänotyp und auch seine Zellen wiesen charakteristische FA-Merkmale auf. Der zelluläre Phänotyp ließ sich durch FAAP100WT komplementieren, sodass die Pathogenität der Mutation bewiesen war. Unterstützend dazu wurden mithilfe des CRISPR/Cas9-Systems weitere FAAP100-defiziente Zelllinien generiert. Diese zeigten ebenfalls einen typischen FA-Phänotyp, welcher sich durch FAAP100WT komplementieren ließ. Die in vitro-Modelle dienten als Grundlage dafür, die Funktion des FA-Kernkomplexes im Allgemeinen und die des Subkomplexes LBP100 im Besonderen besser zu verstehen. Dabei kann nur durch intaktes FAAP100 das LBP100-Modul gebildet und dieses an die DNA-Schadensstelle transportiert werden. Dort leistet FAAP100 einen essentiellen Beitrag für den FANCD2-Monoubiquitinierungsprozess und somit für die Aktivierung der FA-abhängigen DNA-Schadensreparatur. Um die Funktion von FAAP100 auch in vivo zu untersuchen, wurde ein Faap100-/--Mausmodell generiert, das einen mit anderen FA-Mausmodellen vergleichbaren, relativ schweren FA-Phänotyp aufwies. Aufgrund der Ergebnisse lässt sich FAAP100 als neues FA-Gen klassifizieren. Zudem wurde die Rolle des Subkomplexes LBP100 innerhalb des FA-Kernkomplexes weiter aufgeklärt. Beides trägt zu einem besseren Verständnis des FA/BRCA-Signalweges bei. Ein weiterer Teil der vorliegenden Arbeit beschäftigt sich mit der Charakterisierung von FAAP100138, einer bisher nicht validierten Isoform von FAAP100. Durch dieses Protein konnte der zelluläre FA-Phänotyp von FAAP100-defizienten Zelllinien nicht komplementiert werden, jedoch wurden Hinweise auf einen dominant-negativen Effekt von FAAP100138 auf den FA/BRCA-Signalweg gefunden. Dies könnte zu der Erklärung beitragen, warum und wie der Signalweg, beispielsweise in bestimmtem Gewebearten, herunterreguliert wird. Zudem wäre eine Verwendung in der Krebstherapie denkbar.
N2 - Fanconi Anemia (FA) is a rare heterogeneous hereditary disease. It shows a highly variable clinical presentation including congenital malformations, bone marrow failure and increased risk for cancer and endocrine pathologies. The disease is classified as one of the genomic instability disorders that are characterized by failure of DNA damage repair processes. FA shows a typical hypersensitivity toward DNA crosslinking agents (e.g. Mitomycin C, cisplatin). There is an increased rate of chromosomal breakage and cell cycle arrest in the G2 phase. These characteristics are present spontaneously and after incubation with DNA crosslinking agents. The genetic defect can be found in one of the 22 reported FA genes (FANCA, -B, -C, -D1, -D2, -E, -F, -G, -I, -J, -L, -M, -N, -O, -P, -Q, -R, -S, -T, -U, -V, -W) or yet unknown FA genes. FA gene defects are inherited in an autosomal recessive way with the exceptions of FANCR (dominant negative de novo mutations) and FANCB (X-linked). Together with other proteins, the FA gene products establish the FA/BRCA pathway. The key event of this pathway is the monoubiquitination of FANCD2 and FANCI (ID2 complex). From this point it is possible to differentiate between upstream and downstream FA proteins. The latter are directly involved in FA-dependent DNA repair processes. The upstream positioned FA proteins form the FA core complex that includes FA and FA-associated proteins (FAAPs). The FA core complex is responsible for the monoubiquitination of FANCD2 and FANCI. To date no pathogenic human mutations of the FAAPs have been described. Among these proteins is FAAP100 which together with FANCB and FANCL forms the subcomplex LBP100 within the FA core complex.
In the present thesis a closer characterization of this protein has been achieved. In an amniotic cell line a homozygous missense mutation could be identified. The affected fetus displayed a typical FA phenotype and the cells also showed characteristics of FA. The cellular phenotype was complemented by FAAP100WT, thus proving the pathogenicity of the mutation. Supporting this result, additional FAAP100-deficient cell lines have been generated using the CRISPR/Cas9 system. These also exhibited a typical FA cellular phenotype which could be complemented by FAAP100WT. In vitro models served as a basis for better understanding the function of the FA core complex in general and of the LBP100 subcomplex in particular. Only in the presence of an intact FAAP100 the LBP100 module can be formed and transported to sites of DNA interstrand crosslinks. There, FAAP100 significantly contributes to the FANCD2 monoubiquitination process and thus to the activation of FA-dependent DNA damage repair. In order to also examine the function of FAAP100 in vivo, an Faap100-/- mouse model has been generated which shows a relatively severe FA phenotype comparable to other FA mouse models. Because of these results FAAP100 can be categorized as a new FA gene. Moreover, the role of the LBP100 subcomplex within the FA core complex was further elucidated and a better understanding of the FA/BRCA pathway was achieved. Another part of this thesis deals with the characterization of FAAP100138, a hitherto not validated isoform of FAAP100. The cellular FA phenotype of FAAP100-deficient cell lines could not be complemented by this isoform. However, there are clues pointing to a dominant negative effect of FAAP100138 on the FA/BRCA pathway. This finding could serve as a potential explanation of how and why the FA signaling pathway is downregulated in certain tissues. A therapeutic application for cancer of FAAP100138 appears possible.
KW - Fanconi-Anämie
KW - DNA-Reparatur
KW - FAAP100
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171669
ER -
TY - JOUR
A1 - Schneider, Eberhard
A1 - Pliushch, Galyna
A1 - El Hajj, Nady
A1 - Galetzka, Danuta
A1 - Puhl, Alexander
A1 - Schorsch, Martin
A1 - Frauenknecht, Katrin
A1 - Riepert, Thomas
A1 - Tresch, Achim
A1 - Mueller, Annette M.
A1 - Coerdt, Wiltrud
A1 - Zechner, Ulrich
A1 - Haaf, Thomas
T1 - Spatial, temporal and interindividual epigenetic variation of functionally important DNA methylation patterns
N2 - DNA methylation is an epigenetic modification that plays an important role in gene regulation. It can be influenced by stochastic events, environmental factors and developmental programs. However, little is known about the natural variation of genespecific methylation patterns. In this study, we performed quantitative methylation analyses of six differentially methylated imprinted genes (H19, MEG3, LIT1, NESP55, PEG3 and SNRPN), one hypermethylated pluripotency gene (OCT4) and one hypomethylated tumor suppressor gene (APC) in chorionic villus, fetal and adult cortex, and adult blood samples. Both average methylation level and range of methylation variation depended on the gene locus, tissue type and/or developmental stage. We found considerable variability of functionally important methylation patterns among unrelated healthy individuals and a trend toward more similar methylation levels in monozygotic twins than in dizygotic twins. Imprinted genes showed relatively little methylation changes associated with aging in individuals who are >25 years. The relative differences in methylation among neighboring CpGs in the generally hypomethylated APC promoter may not only reflect stochastic fluctuations but also depend on the tissue type. Our results are consistent with the view that most methylation variation may arise after fertilization, leading to epigenetic mosaicism.
KW - Medizin
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68371
ER -
TY - JOUR
A1 - Weis, Eva
A1 - Schoen, Holger
A1 - Victor, Anja
A1 - Spix, Claudia
A1 - Ludwig, Marco
A1 - Schneider-Raetzke, Brigitte
A1 - Kohlschmidt, Nicolai
A1 - Bartsch, Oliver
A1 - Gerhold-Ay, Aslihan
A1 - Boehm, Nils
A1 - Grus, Franz
A1 - Haaf, Thomas
A1 - Galetzka, Danuta
T1 - Reduced mRNA and Protein Expression of the Genomic Caretaker RAD9A in Primary Fibroblasts of Individuals with Childhood and Independent Second Cancer
N2 - Background: The etiology of secondary cancer in childhood cancer survivors is largely unclear. Exposure of normal somatic cells to radiation and/or chemotherapy can damage DNA and if not all DNA lesions are properly fixed, the mis-repair may lead to pathological consequences. It is plausible to assume that genetic differences, i.e. in the pathways responsible for cell cycle control and DNA repair, play a critical role in the development of secondary cancer. Methodology/Findings: To identify factors that may influence the susceptibility for second cancer formation, we recruited 20 individuals who survived a childhood malignancy and then developed a second cancer as well as 20 carefully matched control individuals with childhood malignancy but without a second cancer. By antibody microarrays, we screened primary fibroblasts of matched patients for differences in the amount of representative DNA repair-associated proteins. We found constitutively decreased levels of RAD9A and several other DNA repair proteins in two-cancer patients, compared to onecancer patients. The RAD9A protein level increased in response to DNA damage, however to a lesser extent in the twocancer patients. Quantification of mRNA expression by real-time RT PCR revealed lower RAD9A mRNA levels in both untreated and 1 Gy c-irradiated cells of two-cancer patients. Conclusions/Significance: Collectively, our results support the idea that modulation of RAD9A and other cell cycle arrest and DNA repair proteins contribute to the risk of developing a second malignancy in childhood cancer patients.
KW - Medizin
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-74777
ER -
TY - THES
A1 - Löwe, Julia Irmgard
T1 - Genetische Erkrankungen bei Figuren in der Märchensammlung der Brüder Grimm
T1 - Genetic diseases in the characters of the brothers Grimm fairy-tale collection
N2 - Wissenschaftliche Untersuchung über einzelne humangenetische Erkrankungsbilder, welche mit bestimmten Märchenfiguren korreliert werden können.
N2 - Scientific study of human genetic diseases, which can be correlated with certain fairy-tale characters.
KW - Brüder Grimm
KW - genetische Erkrankungen
KW - brothers grimm
KW - genetic diseases
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-69774
ER -
TY - THES
A1 - Kenner, Julia Elke
T1 - Inzidenzschätzung der Gliedergürtelmuskeldystrophien für Deutschland
T1 - Estimation on the incidence of limb-girdle muscular dystrophies for Germany
N2 - Die LGMD ist eine seltene Erbkrankheit der Muskelfasern, die zur Abnahme der Muskelmasse und der Muskelkraft führt. Das Institut der Humangenetik der Universität Würzburg ist eine der wenigen Stellen in Deutschland, die die molekulargenetische Diagnostik der LGMD 1B, 1C, 2A, 2B, 2D und 2I anbietet. Demnach liegen hier viele Daten vor und anhand dieser Daten konnten die Inzidenzen dieser Formen für Deutschland geschätzt werden. Zur Schätzung der LGMD-Inzidenz wurde eine andere Erkrankung herangezogen, die ähnlich selten auftritt wie die LGMD: DM1 und DM2. Die Schätzung ergab eine Inzidenz von 1: 33 000 für die autosomal-rezessiven Formen der LGMD und eine Inzidenz von 1: 272 000 für die autosomal-dominanten Formen der LGMD für Deutschland. Vergleicht man diese Daten mit den Daten aus der Weltliteratur , sieht man, dass die Häufigkeiten nahezu identisch sind.
N2 - LGMD is a rare hereditary disease of muscular fibres which leads to a decrease in muscle mass and muscle strength. The 'Institut der Humangenetik' at Würzburg University is one of the few bodies in Germany that offers molecular genetic diagnosis of LGMD types 1B, 1C, 2A, 2B, 2D, and 2I. Accordingly, it offers a lot of data which allow an estimation of the incidence of these types for Germany. For the estimation of LGMD incidence, another disease that occurs similarly rarely, is used for comparison: DM1 and DM2. The estimation resulted in an incidence of 1: 33,000 for the autosomal recessive forms of LGMD and an incidence of 1: 272,000 for the autosomal dominant forms of LGMD for Germany. A comparison of these data with data from international literature leads to the result that the incidences are almost identical.
KW - Inzidenz
KW - Gliedergürtelmuskeldystrophie
KW - Inzidenzschätzung
KW - Muskeldystrophie
KW - autosomal-dominant
KW - autosomal-rezessiv
KW - incidence
KW - limb-girdle muscular dystrophies
KW - autosomal recessive
KW - autosomal dominant
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75562
ER -
TY - JOUR
A1 - Gavvovidis, Ioannis
A1 - Rost, Isabell
A1 - Trimborn, Marc
A1 - Kaiser, Frank J.
A1 - Purps, Josephine
A1 - Wiek, Konstanze
A1 - Haneberg, Helmut
A1 - Neitzel, Heidemarie
A1 - Schindler, Detlev
T1 - A Novel MCPH1 Isoform Complements the Defective Chromosome Condensation of Human MCPH1-Deficient Cells
N2 - Biallelic mutations in MCPH1 cause primary microcephaly (MCPH) with the cellular phenotype of defective chromosome condensation. MCPH1 encodes a multifunctional protein that notably is involved in brain development, regulation of chromosome condensation, and DNA damage response. In the present studies, we detected that MCPH1 encodes several distinct transcripts, including two major forms: full-length MCPH1 (MCPH1-FL) and a second transcript lacking the six 39 exons (MCPH1De9–14). Both variants show comparable tissue-specific expression patterns, demonstrate nuclear localization that is mediated independently via separate NLS motifs, and are more abundant in certain fetal than adult organs. In addition, the expression of either isoform complements the chromosome condensation defect found in genetically MCPH1-deficient or MCPH1 siRNA-depleted cells, demonstrating a redundancy of both MCPH1 isoforms for the regulation of chromosome condensation. Strikingly however, both transcripts are regulated antagonistically during cell-cycle progression and there are functional differences between the isoforms with regard to the DNA damage response; MCPH1-FL localizes to phosphorylated H2AX repair foci following ionizing irradiation, while MCPH1De9–14 was evenly distributed in the nucleus. In summary, our results demonstrate here that MCPH1 encodes different isoforms that are differentially regulated at the transcript level and have different functions at the protein level.
KW - MCPH1
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75050
ER -
TY - THES
A1 - Weis, Claudia
T1 - Berechnungen der Lebenserkrankungswahrscheinlichkeit bei familiärem Brustkrebs - Vergleich von Methoden
T1 - Lifetime risk calculation for familial breast cancer - comparison of methods
N2 - Diese Arbeit vergleicht verschiedene Methoden zur Berechung der Lebenserkrankungswahrscheinlichkeit bei familiärem Brustkrebs. Dabei handelt es sich um Tabellen von Chang-Claude und die Computerprogramme Cyrillic Version 2.1 sowie IBIS Breast Cancer Risk Evaluation Tool. Es stellte sich heraus, dass sich die Ergebnisse der Modelle nicht wesentlich voneinander unterscheiden.
N2 - This paper compares different models of lifetime risk calculation for familial breast cancer. These were tables of Chang-Claude and the computer programmes Cyrillic Version 2.1 and IBIS Breast Cancer Risk Evaluation Tool. It is shown that there is no distinct difference between the results of calculated risks.
KW - Brustkrebs
KW - Risiko
KW - Berechnung
KW - breast cancer
KW - risk
KW - calculation
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-74027
ER -
TY - JOUR
A1 - Meier, Daniel
A1 - Schindler, Detlev
T1 - Fanconi Anemia Core Complex Gene Promoters Harbor Conserved Transcription Regulatory Elements
N2 - The Fanconi anemia (FA) gene family is a recent addition to the complex network of proteins that respond to and repair certain types of DNA damage in the human genome. Since little is known about the regulation of this novel group of genes at the DNA level, we characterized the promoters of the eight genes (FANCA, B, C, E, F, G, L and M) that compose the FA core complex. The promoters of these genes show the characteristic attributes of housekeeping genes, such as a high GC content and CpG islands, a lack of TATA boxes and a low conservation. The promoters functioned in a monodirectional way and were, in their most active regions, comparable in strength to the SV40 promoter in our reporter plasmids. They were also marked by a distinctive transcriptional start site (TSS). In the 59 region of each promoter, we identified a region that was able to negatively regulate the promoter activity in HeLa and HEK 293 cells in isolation. The central and 39 regions of the promoter sequences harbor binding sites for several common and rare transcription factors, including STAT, SMAD, E2F, AP1 and YY1, which indicates that there may be cross-connections to several established regulatory pathways. Electrophoretic mobility shift assays and siRNA experiments confirmed the shared regulatory responses between the prominent members of the TGF-b and JAK/STAT pathways and members of the FA core complex. Although the promoters are not well conserved, they share region and sequence specific regulatory motifs and transcription factor binding sites (TBFs), and we identified a bi-partite nature to these promoters. These results support a hypothesis based on the co-evolution of the FA core complex genes that was expanded to include their promoters.
KW - Fanconi-Anämie
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68917
ER -
TY - THES
A1 - Schleider, Elisa
T1 - Angiogenese-Modellsysteme zur Funktionsanalyse des humanen CCM3 Proteins
T1 - Angiogenesis in vitro modeling of human CCM3 function
N2 - Zerebrovaskuläre kavernöse Malformationen (CCM) sind Blutgefäßfehlbildungen, welche hauptsächlich im Gehirn vorkommen. Sie sind gekennzeichnet durch stark dilatierte kapillarähnliche Gefäße mit niedriger Flussrate („slow-flow lesions“). Intervenierendes Gehirnparenchym fehlt ebenso wie Perizyten oder glatte Gefäßmuskelzellen. Die klinischen Symptome reichen von starken Kopfschmerzen über Epilepsie bis hin zum Schlaganfall. Dennoch bleiben viele Kavernomträger aufgrund unvollständiger Penetranz ihr Leben lang asymptomatisch. Die Prävalenz beträgt ca. 0,5% in der Gesamtbevölkerung. Es gibt sowohl sporadische als auch dominant vererbte Krankheitsformen. In den letzten Jahren konnten 3 Gene ursächlich mit der Krankheit in Verbindung gebracht werden. Mutationen in CCM1, CCM2 oder CCM3 führen zu einem nicht unterscheidbaren klinischen Phänotyp. Alle drei Proteine bilden einen ternären Komplex in vitro, was eine Beteiligung an einem gemeinsamen molekularen Signalweg bekräftigt. Während die Proteine CCM1 und CCM2 in den letzten Jahren umfangreich erforscht wurden, ist über das CCM3-Protein bis heute wenig bekannt. In dieser Arbeit konnte gezeigt werden, dass CCM3 eine wichtige Rolle in der Angiogenese spielt und diese bei Überexpression in humanen Endothelzellen stark negativ reguliert: die Migration, die Proliferation und die Fähigkeit, kapillarähnliche Strukturen in Matrix-Gelen zu bilden kommt nahezu zum Erliegen. Ein gegenläufiger Effekt nach siRNA induziertem Knock-down von CCM3 war weniger stark ausgeprägt. Einzig die Fähigkeit, gefäßähnliche Strukturen in Matrigelen zu bilden, war erhöht. Um weiterhin Klarheit über die intrazellulären, von CCM3 beeinflussten Signalwege zu schaffen, wurden Tyrosin Kinase Arrays durchgeführt, bei welchen CCM3-überexprimierende HUVEC Lysate mit Kontrolllysaten verglichen wurden. Dabei stellte sich heraus, dass 5 Substrate signifikant erhöht phosphoryliert wurden: der Discoidin Domänen Rezeptor 1 (discoidin domain receptor; DDR1), die duale spezifitätstyrosinphosphorylierungsregulierte Kinase 1A (dual specificity tyrosine-phosphorylation-regulated kinase 1A; DYR1A), die Protoonkogen Tyrosin- Protein Kinase FER (proto-oncogene tyrosine-protein kinase FER; FER), die fynbezogene Kinase (Fyn-related kinase; FRK) und die phosphoinositolabhängige Kinase 1 (Phosphoinositide-dependent kinase 1, PDPK-1). Im Folgenden bestätigten Western Blot, dass die Überexpression von CCM3 in Endothelzellen die phosphoinositolabhängige Kinase 1 und die nachgeschaltete Serin-Threonin Kinase Akt/PBK aktiviert, welche ein bedeutsames Überlebenssignal der Zelle darstellt. Schließlich konnte gezeigt werden, dass CCM3 nicht nur antiangiogen, sondern auch antiapoptotisch wirkt. Die Ergebnisse der vorliegenden Arbeit legen nahe, dass CCM3 für die Integrität des ruhenden, adulten Endothelbettes wichtig ist.
N2 - Cerebral cavernous malformations are slow-flow vascular lesions, mainly located in the brain. They consist of blood-filled dilated capillary-like vessels without brain parenchyma or mural cells. Clinical symptoms include intense headaches, epilepsy and stroke. However, about 40% of lesion carriers live without any symptoms throughout their lives due to incomplete penetrance. The disease prevalence is 0.5% in the population. Sporadic as well as autosomal-dominantly inherited familial forms exist. In recent years, 3 disease-related genes have been identified. Mutations within CCM1, CCM2 or CCM3 lead to indistinguishable clinical phenotypes. All three proteins form a ternary complex in vitro, confirming their participation in one main signaling pathway. While CCM1 and CCM2 have been explored to a great extent over the past years, little is known about CCM3 and its function so far. In this study, we show that CCM3 plays an important role in angiogenesis. Upon overexpression it has strong negative effects in endothelial cells. The ability to migrate, proliferate and to form capillary-like structures in matrix gels is significantly impaired. Knockdown experiments with siRNA against CCM3 did not reveal such distinct effects. Only the ability to form capillary-like structures was elevated. To identify signaling pathways modulated by CCM3, tyrosine kinase arrays were conducted. Lysates from HUVECs overexpressing CCM3 were compared with control lysates. Five substrates revealed significantly increased phosphorylation: the discoidin domain receptor 1 (DDR1), the dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYR1A), the proto-oncogene tyrosine-protein kinase FER (FER), the fyn-related kinase (FRK) and the Phosphoinositidedependent kinase 1 (PDPK-1). The candidate 3-Phosphoinositide-dependent protein kinase- 1 is an important upstream activator of the serine-threonine kinase Akt/PKB. Subsequent experiments confirmed and demonstrated that p-PDPK-1 and p-Akt are activated in lysates overexpressing CCM3. In agreement with the fact that Akt is important for cell survival, we could finally show that CCM3 is both antiangiogenic and antiapoptotic. Our data suggest that CCM3 plays a role in maintaining quiescence of adult vascular endothelial cells.
KW - Blutgefäß
KW - Missbildung
KW - Gehirn
KW - Genanalyse
KW - Endothelzelle
KW - Angiogenese
KW - CCM3
KW - Endothelzellen
KW - CCM3
KW - endothelial cells
KW - angiogenesis
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-51504
N1 - Includes articles:
- Stahl, S., Gaetzner, S., Voss, K., Brackertz, B., Schleider, E., Sürücü, O., Kunze, E., Netzer, C., Korenke, C., Finckh, U., Habek, M., Poljakovic, Z., Elbracht, M., Rudnik-Schöneborn, S., Bertalanffy, H., Sure, U., Felbor, U. (2007) Novel CCM1, CCM2, and CCM3 mutations in patients with cerebral cavernous malformations: in-frame deletion in CCM2 prevents formation of a CCM1/CCM2/CCM3 protein complex. Hum Mutat, 29, 709-717.
- Voss, K., Stahl, S., Reinders, J., Hogan, B.M., Schleider, E., Schulte-Merker, S., Felbor, U. (2009) Functional analysis of human and zebrafish 18 amino acid in-frame deletion pave the way for domain mapping of the cerebral cavernous malformation 3 (CCM3) protein. Hum Mutat, 30, 1003-1011.
- Schleider, E., Stahl, S., Wüstehube, J., Walter, U., Fischer, A., Felbor, U. (2010) Evidence for anti-angiogenic and pro-survival functions of the cerebral cavernous malformation protein 3. Neurogenetics, submitted
ER -
TY - THES
A1 - Schneider, Eberhard
T1 - Identifizierung und Charakterisierung von Genen für sensorineurale Hörstörungen
T1 - Identification and characterization of genes responsible for sensorineural deafness
N2 - Ungefähr 1 -3 Lebendgeborene von 1000 sind von einer Hörstörung betroffen, wovon etwa 60% der Fälle genetisch bedingt sind und in der Mehrzahl einem autosomal rezessiven Erbgang unterliegen. Die Ursachen dieser, zumeist das Innenohr betreffenden, Schallempfindungsstörungen sind äußerst heterogen. Rund 50 Gene konnten bisher mit angeborener, nicht-syndromaler Schallempfindungsschwerhörigkeit in kausalen Zusammenhang gebracht werden, mit GJB2 als dem bislang bedeutendsten, das für bis zu 50% aller Fälle verantwortlich ist. Die Identifizierung weiterer Hörstörungsgene und deren Charakterisierung war Gegenstand dieser Arbeit. Dafür wurden Positionsklonierungsverfahren einerseits und Patienten-screenings andererseits, angewandt. Wir fanden eine homozygote, reziproke Translokation 46,XY,t(10;11),t(10;11) bei einem Patienten mit kongenitaler Schallempfindungsschwerhörigkeit. Beide Eltern und vier weitere Geschwister waren heterozygote Träger der Translokation. Nach der Einengung der Bruchpunktregionen durch Fluoreszenz in situ Hybridisierung (FISH) von spezifischen BAC-Klonen, konnte der exakte Bruchpunkt mittels Vektor-Ligation der Fusionsfragmente und anschließender Sequenzierung bestimmt werden. PDZD7 ist ein PDZ-Domänen-kodierendes Gen auf Chromosom 10, das durch die Translokation beim Patienten zerrissen ist. PDZD7 ist ein Paralog zu den PDZDomänen enthaltenden Genen Harmonin und Whirlin. Mutationen in beiden Genen können kongenitale nicht-syndromale Taubheit und das Usher-Syndrom verursachen, eine Erkrankung mit Taub- und Blindheit. Funktionelle Protein-Protein Interaktionsstudien und Genexpressionsmessungen konnten zeigen, dass PDZD7 mit den beiden Usher-Proteinen interagiert und im menschlichen Innenohr exprimiert wird. Diese Daten unterstützen eine starke Evidenz für PDZD7 als syndromales und nicht-syndromales Hörstörungsgen. Weiterhin wurden durch Screenings eines Hörstörungspatientenkollektives (n=534) genetische und epigentische, möglicherweise pathogene Mechanismen charakterisiert. Diese Screenings wurden für PDZD7, CX30, CX30.3, CX43 (Exomsequenzierung); OTOF, KCNE1 (SNP-Typisierung); del(chr13:19,837,344- 19,968,698) (Deletionsscreening) und GJB2 (Promotermethylierung) durchgeführt.
N2 - Congenital deafness occurs with a frequency of 1 -3 in 1000 live births. Genetic defects cause nearly 60% of all cases with 70% of them being autosomal recessive disorders. There are heterogenous reasons for genetic hearing loss which affect mostly structures of the inner ear. To date some 50 genes could have been linked to sensorineural non-syndromic deafness. Among them GJB2 is the most prominent and important gene and it accounts for up to 50% of all cases. Positional cloning and screening of patients had been applied for the identification and characterization of additional deafness genes which was an issue of this work. A homozygous reciprocal translocation 46,XY,t(10;11),t(10;11) was detected in a patient with congenital non-syndromic sensorineural deafness. Both parents and their four other children were heterozygous translocation carriers. Fluorescence in situ Hybridisation (FISH) of region-specific clones to patient chromosomes was used to narrow down the breakpoint regions. Vector ligation of junction fragments were cloned and subsequently sequenced to localize the exact breakpoint. PDZD7, a PDZ domain coding gene on chromosome 10, was disrupted by the chromosomal break. PDZD7 is a paralog of PDZ domain containing genes harmonin and whirlin. Mutations in both genes can cause congenital non-syndromic deafness and/or Usher syndrome. Functional protein-protein interaction assays and gene expression experiments revealed that PDZD7 is integrated in the Usher network and is expressed in the human inner ear, respectively. These data support strongly that PDZD7 is a further autosomal recessive deafness- and Usher syndrome-gene. Further on we screened a panel of genes in deafness patients (n=534) to characterize potentially pathogenic genetic and epigenetic mechanisms. The analysed genes had been PDZD7, CX30, CX30.3, CX43 (exome-sequencing); OTOF, KCNE1 (SNP-genotyping); del(chr13:19,837,344-19,968,698) (deletionscreening) and GJB2 (promotermethylation).
KW - Hörstörung
KW - Lautwahrnehmung
KW - Erbkrankheit
KW - congenital
KW - deafness
KW - sensorineural
KW - genetic
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-51231
ER -