TY - JOUR A1 - Bernards, R. A1 - Schackleford, G. M. A1 - Gerber, M. R. A1 - Horowitz, J. M. A1 - Friend, S. H. A1 - Schartl, Manfred A1 - Bogenmann, E. A1 - Rapaport, J. M. A1 - Mcgee, T. A1 - Dryja, T. P. T1 - Structure and expression of the murine retinoblastoma gene and characterization of its encoded protein N2 - No abstract available KW - Physiologische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61819 ER - TY - JOUR A1 - Matos, I A1 - Machado, M. P. A1 - Schartl, M. A1 - Coelho, M. M. T1 - Gene expression dosage regulation in an allopolyploid fish JF - PLoS ONE N2 - How allopolyploids are able not only to cope but profit from their condition is a question that remains elusive, but is of great importance within the context of successful allopolyploid evolution. One outstanding example of successful allopolyploidy is the endemic Iberian cyprinid Squalius alburnoides. Previously, based on the evaluation of a few genes, it was reported that the transcription levels between diploid and triploid S. alburnoides were similar. If this phenomenon occurs on a full genomic scale, a wide functional "diploidization'' could be related to the success of these polyploids. We generated RNA-seq data from whole juvenile fish and from adult livers, to perform the first comparative quantitative transcriptomic analysis between diploid and triploid individuals of a vertebrate allopolyploid. Together with an assay to estimate relative expression per cell, it was possible to infer the relative sizes of transcriptomes. This showed that diploid and triploid S. alburnoides hybrids have similar liver transcriptome sizes. This in turn made it valid to directly compare the S. alburnoides RNA-seq transcript data sets and obtain a profile of dosage responses across the S. alburnoides transcriptome. We found that 64% of transcripts in juveniles' samples and 44% in liver samples differed less than twofold between diploid and triploid hybrids (similar expression). Yet, respectively 29% and 15% of transcripts presented accurate dosage compensation (PAA/PA expression ratio of 1 instead of 1.5). Therefore, an exact functional diploidization of the triploid genome does not occur, but a significant down regulation of gene expression in triploids was observed. However, for those genes with similar expression levels between diploids and triploids, expression is not globally strictly proportional to gene dosage nor is it set to a perfect diploid level. This quantitative expression flexibility may be a strong contributor to overcome the genomic shock, and be an immediate evolutionary advantage of allopolyploids. KW - RNA-Seq KW - balance hypothesis KW - hybrids KW - genome KW - maize KW - Squalius alburnoides KW - cell size KW - evolution KW - heterosis KW - complex Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143565 VL - 10 IS - 3 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 - Forconi, Mariko A1 - Canapa, Adriana A1 - Barucca, Marco A1 - Biscotti, Maria A. A1 - Capriglione, Teresa A1 - Buonocore, Francesco A1 - Fausto, Anna M. A1 - Makapedua, Daisy M. A1 - Pallavicini, Alberto A1 - Gerdol, Marco A1 - De Moro, Gianluca A1 - Scapigliati, Giuseppe A1 - Olmo, Ettore A1 - Schartl, Manfred T1 - Characterization of Sex Determination and Sex Differentiation Genes in Latimeria JF - PLoS ONE N2 - Genes involved in sex determination and differentiation have been identified in mice, humans, chickens, reptiles, amphibians and teleost fishes. However, little is known of their functional conservation, and it is unclear whether there is a common set of genes shared by all vertebrates. Coelacanths, basal Sarcopterygians and unique "living fossils", could help establish an inventory of the ancestral genes involved in these important developmental processes and provide insights into their components. In this study 33 genes from the genome of Latimeria chalumnae and from the liver and testis transcriptomes of Latimeria menadoensis, implicated in sex determination and differentiation, were identified and characterized and their expression levels measured. Interesting findings were obtained for GSDF, previously identified only in teleosts and now characterized for the first time in the sarcopterygian lineage; FGF9, which is not found in teleosts; and DMRT1, whose expression in adult gonads has recently been related to maintenance of sexual identity. The gene repertoire and testis-specific gene expression documented in coelacanths demonstrate a greater similarity to modern fishes and point to unexpected changes in the gene regulatory network governing sexual development. KW - medaka fish KW - mullerian hormone AMH KW - DM-domain gene KW - oryzias latipes KW - monodelphis domestica KW - oreochromis niloticus KW - dimorphic expression KW - molecular mechanisms KW - genomic organization KW - regulatory regions Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130995 VL - 8 IS - 4 ER - TY - JOUR A1 - Leikam, C A1 - Hufnagel, AL A1 - Otto, C A1 - Murphy, DJ A1 - Mühling, B A1 - Kneitz, S A1 - Nanda, I A1 - Schmid, M A1 - Wagner, TU A1 - Haferkamp, S A1 - Bröcker, E-B A1 - Schartl, M A1 - Meierjohann, S T1 - In vitro evidence for senescent multinucleated melanocytes as a source for tumor-initiating cells JF - Cell Death and Disease N2 - Oncogenic signaling in melanocytes results in oncogene-induced senescence (OIS), a stable cell-cycle arrest frequently characterized by a bi-or multinuclear phenotype that is considered as a barrier to cancer progression. However, the long-sustained conviction that senescence is a truly irreversible process has recently been challenged. Still, it is not known whether cells driven into OIS can progress to cancer and thereby pose a potential threat. Here, we show that prolonged expression of the melanoma oncogene N-RAS\(^{61K}\) in pigment cells overcomes OIS by triggering the emergence of tumor-initiating mononucleated stem-like cells from senescent cells. This progeny is dedifferentiated, highly proliferative, anoikis-resistant and induces fast growing, metastatic tumors. Our data describe that differentiated cells, which are driven into senescence by an oncogene, use this senescence state as trigger for tumor transformation, giving rise to highly aggressive tumor-initiating cells. These observations provide the first experimental in vitro evidence for the evasion of OIS on the cellular level and ensuing transformation. KW - reactive oxygen KW - human melanoma KW - MITF KW - cancer KW - skin KW - DNA damage KW - kappa-B KW - oncogene-induced senescence KW - cellular senescence Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148718 VL - 6 IS - e1711 ER - TY - JOUR A1 - Martinez-Bengochea, A. L. A1 - Kneitz, S. A1 - Herpin, A. A1 - Nobrega, R. H. A1 - Adolfi, M. C. A1 - Schartl, M. T1 - Sexual development dysgenesis in interspecific hybrids of Medaka fish JF - Scientific Reports N2 - Fish are amongst vertebrates the group with the highest diversity of known sex-determining genes. Particularly, the genus Oryzias is a suitable taxon to understand how different sex determination genetic networks evolved in closely related species. Two closely related species, O. latipes and O. curvinotus, do not only share the same XX/XY sex chromosome system, but also the same male sex-determining gene, dmrt1bY. We performed whole mRNA transcriptomes and morphology analyses of the gonads of hybrids resulting from reciprocal crosses between O. latipes and O. curvinotus. XY male hybrids, presenting meiotic arrest and no production of sperm were sterile, and about 30% of the XY hybrids underwent male-to-female sex reversal. Both XX and XY hybrid females exhibited reduced fertility and developed ovotestis while aging. Transcriptome data showed that male-related genes are upregulated in the XX and XY female hybrids. The transcriptomes of both types of female and of the male gonads are characterized by upregulation of meiosis and germ cell differentiation genes. Differences in the parental species in the downstream pathways of sexual development could explain sex reversal, sterility, and the development of intersex gonads in the hybrids. We hypothesize that male-to-female sex reversal may be connected to a different development time between species at which dmrt1bY expression starts. Our results provide molecular clues for the proximate mechanisms of hybrid incompatibility and Haldane’s rule. KW - sexual development dysgenesis KW - Medaka fish KW - sex-determining genes. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300295 VL - 12 IS - 1 ER - TY - JOUR A1 - Matos, Isa A1 - Sucena, Èlio A1 - Machado, Miguel P A1 - Gardner, Rui A1 - Inácio, Ângela A1 - Schartl, Manfred A1 - Coelho, Maria M T1 - Ploidy mosaicism and allele-specific gene expression differences in the allopolyploid \(Squalius\) \(alburnoides\) JF - BMC Genetics N2 - Background Squalius alburnoides is an Iberian cyprinid fish resulting from an interspecific hybridisation between Squalius pyrenaicus females (P genome) and males of an unknown Anaecypris hispanica- like species (A genome). S. alburnoides is an allopolyploid hybridogenetic complex, which makes it a likely candidate for ploidy mosaicism occurrence, and is also an interesting model to address questions about gene expression regulation and genomic interactions. Indeed, it was previously suggested that in S. alburnoides triploids (PAA composition) silencing of one of the three alleles (mainly of the P allele) occurs. However, not a whole haplome is inactivated but a more or less random inactivation of alleles varying between individuals and even between organs of the same fish was seen. In this work we intended to correlate expression differences between individuals and/or between organs to the occurrence of mosaicism, evaluating if mosaics could explain previous observations and its impact on the assessment of gene expression patterns. Results To achieve our goal, we developed flow cytometry and cell sorting protocols for this system generating more homogenous cellular and transcriptional samples. With this set-up we detected 10% ploidy mosaicism within the S. alburnoides complex, and determined the allelic expression profiles of ubiquitously expressed genes (rpl8; gapdh and β-actin) in cells from liver and kidney of mosaic and non-mosaic individuals coming from different rivers over a wide geographic range. Conclusions Ploidy mosaicism occurs sporadically within the S. alburnoides complex, but in a frequency significantly higher than reported for other organisms. Moreover, we could exclude the influence of this phenomenon on the detection of variable allelic expression profiles of ubiquitously expressed genes (rpl8; gapdh and β-actin) in cells from liver and kidney of triploid individuals. Finally, we determined that the expression patterns previously detected only in a narrow geographic range is not a local restricted phenomenon but is pervasive in rivers where S. pyrenaicus is sympatric with S. alburnoides. We discuss mechanisms that could lead to the formation of mosaic S. alburnoides and hypothesise about a relaxation of the mechanisms that impose a tight control over mitosis and ploidy control in mixoploids." KW - Squalius alburnoides Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-142879 VL - 12 IS - 101 ER - TY - JOUR A1 - Raulf, F. A1 - Robertson, S. M. A1 - Schartl, Manfred T1 - Evolution of the neuron-specific alternative splicing product of the c-src proto-oncogene N2 - The observation of a slower migrating form of pp6oc-src in neural tissue of chicken and mouse has recently been shown to be due to an alternative transcript form of tbe c-src gene (Martinez et al.: Science 237:411-415, 1987; Levy et al.: Mol Cell Bio17:4142- 4145, 1987). An insertion of 18 basepairs between exons 3 and 4, presumed to be due to alternative splicing of a mini-exon, gives rise to six amino acid residues not found in the non-neuronal (termed flbroblastic) form of pp60\(^{c-src}\). Wehave addressed the question of the evolutionary origin of the c-src neuronal insert · and its functional signiflcance regarding neural-speciflc expression of the c-src gene. To this end we have investigated whether the c-src gene of a lower verlebrate (the teleost fish Xiphophorus) gives rise to a neural-specific transcript in an analogous manner. We could show that the fish c-src gene does encode for a "fibroblastic" and a "neuronal" form of transcript and that the neuronal transcript does indeed arise by way of alternative splicing of a mini-exon. The miniexon is also 18 basepairs long and we could demoostrate directly that this exon lies within the intron separating exons 3 and 4. For comparative purposes we have examined whether the fish c-yes gene, the member of the src gene family most closely related to c-src, also encodes a neural tissue-specific transcript. No evidence for a second transcript form in brain was obtained. This result suggests that the mini-exon arose within the c-src gene lineage sometime between the srclyes gene duplication event and the divergence of the evolutionary lineage giving rise to the teleost fish. Published genomic sequence of src-related genes in Drosophila and our own results with Hydra demoostrate no intron in these species at the analogous location, consistent with first appearance of this mini-exon sometime between 550 and 400 million years ago. KW - Physiologische Chemie KW - Xiphophorus KW - teleost flsh KW - polymerase KW - chain reaction KW - RT -PCR KW - mini-exon KW - pp6oc-src Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61796 ER - TY - JOUR A1 - Wittbrodt, J. A1 - Adam, D. A1 - Malitschek, B. A1 - Maueler, W. A1 - Raulf, F. A1 - Telling, A. A1 - Robertson, M. A1 - Schartl, Manfred T1 - Novel putative receptor tyrosine kinase encoded by the melanoma-inducing Tu locus in Xiphophorus N2 - No abstract available KW - Physiologische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61800 ER - TY - JOUR A1 - Teutschbein, Janka A1 - Haydn, Johannes M. A1 - Samans, Birgit A1 - Krause, Michael A1 - Eilers, Martin A1 - Schartl, Manfred A1 - Meierjohann, Svenja T1 - Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins N2 - Background: Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase) triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Methods: Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Results: Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1), early growth response 1 (Egr1), osteopontin (Opn), insulin-like growth factor binding protein 3 (Igfbp3), dual-specificity phosphatase 4 (Dusp4), and tumor-associated antigen L6 (Taal6). Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Conclusion: Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute new possible molecular players in melanoma development. Specifically, a role of FOSL1 in melanomagenic processes is demonstrated. These data are the basis for future detailed analyses of the investigated target genes. KW - Melanoma Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67900 ER -