@article{SchartlErbeldingDenkHolteretal.1993, author = {Schartl, Manfred and Erbelding-Denk, Claudia and Holter, Sabine and Nanda, Indrajit and Schmid, Michael and Schroder, Johannes H. and Epplen, J{\"o}rg T.}, title = {Reproductive failure of dominant males in the poeciliid fish Limia perugiae determined by DNA fingerprinting}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61643}, year = {1993}, abstract = {Hierarchical structures among male indlviduals in a population are frequently reflected ln differences in aggressive and reproductive behavior and access to the females. In general, sodal dominance requires the Investments, which in turn then may have to be compensated for by high reproductive success. However, this hypothesls has so far only been sufficiently tested in small mating groups (one or two males with one or two females) due to the difficulties of determining paternity by conventional methods. DNA fingerprinting overcomes these problems by offering the possibility to determine genetic relationships and mating patterns within larger groups [Borke, T. (1989) Trends Ecol. Evol. 4, 139-144]. We show here that in the poecUiid fish Limia perugitu, in small matlng groups the dominant male has 8 mating success of 100\%, whereas ln larger groups lts contribution to the offspring unexpectedly drops to zero.}, subject = {Physiologische Chemie}, language = {en} } @article{SchluppParzefallEpplenetal.1992, author = {Schlupp, Ingo and Parzefall, Jakob and Epplen, J{\"o}rg T. and Nanda, Indrajit and Schmid, Michael and Schartl, Manfred}, title = {Pseudomale behaviour and spontaneous masculinization in the all-female teleost Poecilia formosa (Teleostei: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61688}, year = {1992}, abstract = {Pseudosexual behaviour is a rare phenomenon associated with unisexuality in vertebrates. In the gynogenetic, all-female teleost Poecilia formosa, rare individuals occur that resemble males of closely related gonochoristic species both in behaviour and external morphology. These masculinized gynogens and normal gynogens are members of the same clone, as demonstrated by DNA-fingerprinting. The behaviour of these masculinized gynogens is described and compared to the behaviour of the gonochoristic species Poecilia mexicana, P. latipinna and their hybrid as weil as androgen-treated individuals of P. formosa. No statistically significant difTerences were found between masculinized gynogens and hormonetreated individuals nor between the gonochoristic P. mexicana and P. latipinna males. Differences exist between gonochoristic and unisexual species. Passihle causes and effects of masculinized gynogens are discussed.}, subject = {Physiologische Chemie}, language = {en} } @article{NandaSchartlEpplenetal.1993, author = {Nanda, Indrajit and Schartl, Manfred and Epplen, J{\"o}rg T. and Feichtinger, Wolfgang and Schmid, Michael}, title = {Primitive sex chromosomes in poeciliid fishes harbor simple repetitive DNA sequences}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61659}, year = {1993}, abstract = {The demonstration ofthe chromosomal mode ofsex determinationvia genetic experiments as well as the absence of heteromorphic sex chromosomes affirm poeciliid fishes as a unique group among vertebrates that are endowed with the mostprimitive form of sex chromosornes. In many different taxa the evolutionary process involved in the differentiation ofadvanced sex chromosomes is outlined through sex specifically organized repetitive sequences. In this investigation hydridization of synthetic probes specific to genomic simple repeat motifs uncovers a sex-specific hybridization pattern in certain viviparaus fishes ofthe family Poeciliidae. The hybridization pattern together with specific staining ofthe constitutive heterochromatin by C-banding reveals heterogamety in males (Poecilia reticulata) as weil as in females (P. sphenops). In P. velifera, however, C-banding alone fails to unravel the heterogametic status. The female specific W-chromosome can be detected by simple repetitive sequence probes. Therefore, the principal significance of heterochromatization as a means of generating differentiated sex chromosomes is evident.}, subject = {Physiologische Chemie}, language = {en} } @article{SchartlSchluppSchartletal.1991, author = {Schartl, Manfred and Schlupp, Ingo and Schartl, Angelika and Meyer, Manfred K. and Nanda, Indrajit and Schmid, Michael and Epplen, J{\"o}rg T. and Parzefall, Jakob}, title = {On the stability of dispensable constituents of the eukaryotic genome: Stability of coding sequences versus truly hypervariable sequences in a clonal vertebrate, the amazon molly, Poecilia formosa}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61731}, year = {1991}, abstract = {In dooal unisexual vertebrales, the genes specifying the males become dispensable. To study tbe rate of such geoes the gynogeoetic all-female fisb Poecilillfonnolll was treated with androgens. Phenotypic males were obtained that exbibited the complete set of male cbaracteristics of dosely related gooocboristic species, induding body proportions, pigmentation, the extremely complex insemination apparatus of poecil{\"u}d fish, sexual bebavior, and spermatogeoesls. Tbe apparent stabllity of such genic structures, induding those involved in androgen regulation, is contrasted by high instability of noncoding sequeaces. Frequent mutations, thelr donal transmission, and at least two truly hypervariable Iod leading to individual difl'ereaces between these othenrise donal organisms were detected by DNA fingerprinting. These observations substantiate the concept that also in "ameiotic" vertebrates certain compartments of the genome are more prooe to mutatiooal alterations than others.}, subject = {Physiologische Chemie}, language = {en} } @article{SchartlErbeldingDenkNandaetal.1991, author = {Schartl, Manfred and Erbelding-Denk, Claudia and Nanda, Indrajit and Schmid, Michael and Schr{\"o}der, Johannes Horst and Epplen, J{\"o}rg T.}, title = {Mating success of subordinate males in a poeciliid fish species, Limia perugiae}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86349}, year = {1991}, abstract = {No abstract available.}, subject = {Lebendgeb{\"a}rende Zahnkarpfen}, language = {en} } @article{ErbeldingDenkSchroderSchartletal.1994, author = {Erbelding-Denk, Claudia and Schroder, Johannes H. and Schartl, Manfred and Nanda, Indrajit and Schmid, Michael and Epplen, J{\"o}rg T.}, title = {Male polymorphism in Limia perugiae (Pisces: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61573}, year = {1994}, abstract = {The male-polymorphic poeciliid fish, Limia perugiae, a small teleostean endemic to the southeast of the Caribbean island Hispafiola, consists of three male size morphs with uniform females. Large males differentiate at a size va:rying between 25 and 38 mm; intermediate males, between 21 and 25 mm. Under competition, !arge males exhibit an elaborate courtship display, whereas small males show only a sneak-chase behavior. Intermediate males adapt their tactics to the respective competitors. However, all malemorphs can switch from courtship display to sneak-chase behavior. In large mating groups with four males of different size and five or six virgin females, large dominant a-males as weil as small subordinate \(\delta\)-males did not produce any offspring. Unexpectedly, all progeny were sired exclusively by the intemediate subordinate ß- and \(\gamma\)-males. Breeding experiments with the three male morphs can best be explained by a model of Y -linked genes for small and !arge size which are both suspended by the activity of an autosomal recessive repressor responsible for the development of intermediate males. The dominant allele of the recessive repressor, in either its homoorits heterozygous state, activates the Y-chromosomal genes for !arge or small size, respectively. Accordingly, intermediate males may produce male offspring of all size classes, depending on the presence of either the Y-linked gene or the autosomal repressor.}, subject = {Physiologische Chemie}, language = {en} } @article{SchartlNandaSchluppetal.1990, author = {Schartl, Manfred and Nanda, Indrajit and Schlupp, Ingo and Parzefall, Jakob and Schmid, Michael and Epplen, J{\"o}rg T.}, title = {Genetic variation in the clonal vertebrate Poecilia formosa is limited to few truly hypervariable loci}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86359}, year = {1990}, abstract = {No abstract available.}, subject = {Amazon Molly}, language = {en} } @article{DollVonaSchnappetal.2020, author = {Doll, Julia and Vona, Barbara and Schnapp, Linda and R{\"u}schendorf, Franz and Khan, Imran and Khan, Saadullah and Muhammad, Noor and Alam Khan, Sher and Nawaz, Hamed and Khan, Ajmal and Ahmad, Naseer and Kolb, Susanne M. and K{\"u}hlewein, Laura and Labonne, Jonathan D. J. and Layman, Lawrence C. and Hofrichter, Michaela A. H. and R{\"o}der, Tabea and Dittrich, Marcus and M{\"u}ller, Tobias and Graves, Tyler D. and Kong, Il-Keun and Nanda, Indrajit and Kim, Hyung-Goo and Haaf, Thomas}, title = {Genetic Spectrum of Syndromic and Non-Syndromic Hearing Loss in Pakistani Families}, series = {Genes}, volume = {11}, journal = {Genes}, number = {11}, issn = {2073-4425}, doi = {10.3390/genes11111329}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219293}, year = {2020}, abstract = {The current molecular genetic diagnostic rates for hereditary hearing loss (HL) vary considerably according to the population background. Pakistan and other countries with high rates of consanguineous marriages have served as a unique resource for studying rare and novel forms of recessive HL. A combined exome sequencing, bioinformatics analysis, and gene mapping approach for 21 consanguineous Pakistani families revealed 13 pathogenic or likely pathogenic variants in the genes GJB2, MYO7A, FGF3, CDC14A, SLITRK6, CDH23, and MYO15A, with an overall resolve rate of 61.9\%. GJB2 and MYO7A were the most frequently involved genes in this cohort. All the identified variants were either homozygous or compound heterozygous, with two of them not previously described in the literature (15.4\%). Overall, seven missense variants (53.8\%), three nonsense variants (23.1\%), two frameshift variants (15.4\%), and one splice-site variant (7.7\%) were observed. Syndromic HL was identified in five (23.8\%) of the 21 families studied. This study reflects the extreme genetic heterogeneity observed in HL and expands the spectrum of variants in deafness-associated genes.}, language = {en} } @article{FlunkertMaierhoferDittrichetal.2018, author = {Flunkert, Julia and Maierhofer, Anna and Dittrich, Marcus and M{\"u}ller, Tobias and Horvath, Steve and Nanda, Indrajit and Haaf, Thomas}, title = {Genetic and epigenetic changes in clonal descendants of irradiated human fibroblasts}, series = {Experimental Cell Research}, volume = {370}, journal = {Experimental Cell Research}, doi = {10.1016/j.yexcr.2018.06.034}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228177}, pages = {322-332}, year = {2018}, abstract = {To study delayed genetic and epigenetic radiation effects, which may trigger radiation-induced carcinogenesis, we have established single-cell clones from irradiated and non-irradiated primary human fibroblasts. Stable clones were endowed with the same karyotype in all analyzed metaphases after 20 population doublings (PDs), whereas unstable clones displayed mosaics of normal and abnormal karyotypes. To account for variation in radiation sensitivity, all experiments were performed with two different fibroblast strains. After a single X-ray dose of 2 Gy more than half of the irradiated clones exhibited radiation-induced genome instability (RIGI). Irradiated clones displayed an increased rate of loss of chromosome Y (LOY) and copy number variations (CNVs), compared to controls. CNV breakpoints clustered in specific chromosome regions, in particular 3p14.2 and 7q11.21, coinciding with common fragile sites. CNVs affecting the FHIT gene in FRA3B were observed in independent unstable clones and may drive RIGI. Bisulfite pyrosequencing of control clones and the respective primary culture revealed global hypomethylation of ALU, LINE-1, and alpha-satellite repeats as well as rDNA hypermethylation during in vitro ageing. Irradiated clones showed further reduced ALU and alpha-satellite methylation and increased rDNA methylation, compared to controls. Methylation arrays identified several hundred differentially methylated genes and several enriched pathways associated with in vitro ageing. Methylation changes in 259 genes and the MAP kinase signaling pathway were associated with delayed radiation effects (after 20 PDs). Collectively, our results suggest that both genetic (LOY and CNVs) and epigenetic changes occur in the progeny of exposed cells that were not damaged directly by irradiation, likely contributing to radiation-induced carcinogenesis. We did not observe epigenetic differences between stable and unstable irradiated clones. The fact that the DNA methylation (DNAm) age of clones derived from the same primary culture varied greatly suggests that DNAm age of a single cell (represented by a clone) can be quite different from the DNAm age of a tissue. We propose that DNAm age reflects the emergent property of a large number of individual cells whose respective DNAm ages can be highly variable.}, language = {en} } @article{NandaSchoriesSimeonovetal.2022, author = {Nanda, Indrajit and Schories, Susanne and Simeonov, Ivan and Adolfi, Mateus Contar and Du, Kang and Steinlein, Claus and Alsheimer, Manfred and Haaf, Thomas and Schartl, Manfred}, title = {Evolution of the degenerated Y-chromosome of the swamp guppy, Micropoecilia picta}, series = {Cells}, volume = {11}, journal = {Cells}, number = {7}, issn = {2073-4409}, doi = {10.3390/cells11071118}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267242}, year = {2022}, abstract = {The conspicuous colour sexual dimorphism of guppies has made them paradigmatic study objects for sex-linked traits and sex chromosome evolution. Both the X- and Y-chromosomes of the common guppy (Poecilia reticulata) are genetically active and homomorphic, with a large homologous part and a small sex specific region. This feature is considered to emulate the initial stage of sex chromosome evolution. A similar situation has been documented in the related Endler's and Oropuche guppies (P. wingei, P. obscura) indicating a common origin of the Y in this group. A recent molecular study in the swamp guppy (Micropoecilia. picta) reported a low SNP density on the Y, indicating Y-chromosome deterioration. We performed a series of cytological studies on M. picta to show that the Y-chromosome is quite small compared to the X and has accumulated a high content of heterochromatin. Furthermore, the Y-chromosome stands out in displaying CpG clusters around the centromeric region. These cytological findings evidently illustrate that the Y-chromosome in M. picta is indeed highly degenerated. Immunostaining for SYCP3 and MLH1 in pachytene meiocytes revealed that a substantial part of the Y remains associated with the X. A specific MLH1 hotspot site was persistently marked at the distal end of the associated XY structure. These results unveil a landmark of a recombining pseudoautosomal region on the otherwise strongly degenerated Y chromosome of M. picta. Hormone treatments of females revealed that, unexpectedly, no sexually antagonistic color gene is Y-linked in M. picta. All these differences to the Poecilia group of guppies indicate that the trajectories associated with the evolution of sex chromosomes are not in parallel.}, language = {en} }