@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} } @article{GuptaSrivastavaOsmanogluetal.2021, author = {Gupta, Shishir K. and Srivastava, Mugdha and Osmanoglu, {\"O}zge and Xu, Zhuofei and Brakhage, Axel A. and Dandekar, Thomas}, title = {Aspergillus fumigatus versus genus Aspergillus: conservation, adaptive evolution and specific virulence genes}, series = {Microorganisms}, volume = {9}, journal = {Microorganisms}, number = {10}, issn = {2076-2607}, doi = {10.3390/microorganisms9102014}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246318}, year = {2021}, abstract = {Aspergillus is an important fungal genus containing economically important species, as well as pathogenic species of animals and plants. Using eighteen fungal species of the genus Aspergillus, we conducted a comprehensive investigation of conserved genes and their evolution. This also allows us to investigate the selection pressure driving the adaptive evolution in the pathogenic species A. fumigatus. Among single-copy orthologs (SCOs) for A. fumigatus and the closely related species A. fischeri, we identified 122 versus 50 positively selected genes (PSGs), respectively. Moreover, twenty conserved genes of unknown function were established to be positively selected and thus important for adaption. A. fumigatus PSGs interacting with human host proteins show over-representation of adaptive, symbiosis-related, immunomodulatory and virulence-related pathways, such as the TGF-β pathway, insulin receptor signaling, IL1 pathway and interfering with phagosomal GTPase signaling. Additionally, among the virulence factor coding genes, secretory and membrane protein-coding genes in multi-copy gene families, 212 genes underwent positive selection and also suggest increased adaptation, such as fungal immune evasion mechanisms (aspf2), siderophore biosynthesis (sidD), fumarylalanine production (sidE), stress tolerance (atfA) and thermotolerance (sodA). These genes presumably contribute to host adaptation strategies. Genes for the biosynthesis of gliotoxin are shared among all the close relatives of A. fumigatus as an ancient defense mechanism. Positive selection plays a crucial role in the adaptive evolution of A. fumigatus. The genome-wide profile of PSGs provides valuable targets for further research on the mechanisms of immune evasion, antimycotic targeting and understanding fundamental virulence processes.}, language = {en} } @article{GuptaMinochaThapaetal.2022, author = {Gupta, Shishir K. and Minocha, Rashmi and Thapa, Prithivi Jung and Srivastava, Mugdha and Dandekar, Thomas}, title = {Role of the pangolin in origin of SARS-CoV-2: an evolutionary perspective}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {16}, issn = {1422-0067}, doi = {10.3390/ijms23169115}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285995}, year = {2022}, abstract = {After the recent emergence of SARS-CoV-2 infection, unanswered questions remain related to its evolutionary history, path of transmission or divergence and role of recombination. There is emerging evidence on amino acid substitutions occurring in key residues of the receptor-binding domain of the spike glycoprotein in coronavirus isolates from bat and pangolins. In this article, we summarize our current knowledge on the origin of SARS-CoV-2. We also analyze the host ACE2-interacting residues of the receptor-binding domain of spike glycoprotein in SARS-CoV-2 isolates from bats, and compare it to pangolin SARS-CoV-2 isolates collected from Guangdong province (GD Pangolin-CoV) and Guangxi autonomous regions (GX Pangolin-CoV) of South China. Based on our comparative analysis, we support the view that the Guangdong Pangolins are the intermediate hosts that adapted the SARS-CoV-2 and represented a significant evolutionary link in the path of transmission of SARS-CoV-2 virus. We also discuss the role of intermediate hosts in the origin of Omicron.}, language = {en} } @article{DedukhDaCruzKneitzetal.2022, author = {Dedukh, Dmitrij and Da Cruz, Irene and Kneitz, Susanne and Marta, Anatolie and Ormanns, Jenny and Tichop{\´a}d, Tom{\´a}š and Lu, Yuan and Alsheimer, Manfred and Janko, Karel and Schartl, Manfred}, title = {Achiasmatic meiosis in the unisexual Amazon molly, Poecilia formosa}, series = {Chromosome Research}, volume = {30}, journal = {Chromosome Research}, number = {4}, doi = {10.1007/s10577-022-09708-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325128}, pages = {443-457}, year = {2022}, abstract = {Unisexual reproduction, which generates clonal offspring, is an alternative strategy to sexual breeding and occurs even in vertebrates. A wide range of non-sexual reproductive modes have been described, and one of the least understood questions is how such pathways emerged and how they mechanistically proceed. The Amazon molly, Poecilia formosa, needs sperm from males of related species to trigger the parthenogenetic development of diploid eggs. However, the mechanism, of how the unreduced female gametes are produced, remains unclear. Cytological analyses revealed that the chromosomes of primary oocytes initiate pachytene but do not proceed to bivalent formation and meiotic crossovers. Comparing ovary transcriptomes of P. formosa and its sexual parental species revealed expression levels of meiosis-specific genes deviating from P. mexicana but not from P. latipinna. Furthermore, several meiosis genes show biased expression towards one of the two alleles from the parental genomes. We infer from our data that in the Amazon molly diploid oocytes are generated by apomixis due to a failure in the synapsis of homologous chromosomes. The fact that this failure is not reflected in the differential expression of known meiosis genes suggests the underlying molecular mechanism may be dysregulation on the protein level or misexpression of a so far unknown meiosis gene, and/or hybrid dysgenesis because of compromised interaction of proteins from diverged genomes.}, language = {en} }