Chromosoma最新文献

{"title":"Kinesin-5 Eg5 mediates centrosome separation to control spindle assembly in spermatocytes.","authors":"Zhen-Yu She,&nbsp;Ning Zhong,&nbsp;Ya-Lan Wei","doi":"10.1007/s00412-022-00772-5","DOIUrl":"https://doi.org/10.1007/s00412-022-00772-5","url":null,"abstract":"<p><p>Timely and accurate centrosome separation is critical for bipolar spindle organization and faithful chromosome segregation during cell division. Kinesin-5 Eg5 is essential for centrosome separation and spindle organization in somatic cells; however, the detailed functions and mechanisms of Eg5 in spermatocytes remain unclear. In this study, we show that Eg5 proteins are located at spindle microtubules and centrosomes in spermatocytes both in vivo and in vitro. We reveal that the spermatocytes are arrested at metaphase I in seminiferous tubules after Eg5 inhibition. Eg5 ablation results in cell cycle arrest, the formation of monopolar spindle, and chromosome misalignment in cultured GC-2 spd cells. Importantly, we find that the long-term inhibition of Eg5 results in an increased number of centrosomes and chromosomal instability in spermatocytes. Our findings indicate that Eg5 mediates centrosome separation to control spindle assembly and chromosome alignment in spermatocytes, which finally contribute to chromosome stability and faithful cell division of the spermatocytes.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"131 1-2","pages":"87-105"},"PeriodicalIF":1.6,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9230306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Satellitome analysis illuminates the evolution of ZW sex chromosomes of Triportheidae fishes (Teleostei: Characiformes).","authors":"Rafael Kretschmer,&nbsp;Caio Augusto Gomes Goes,&nbsp;Luiz Antônio Carlos Bertollo,&nbsp;Tariq Ezaz,&nbsp;Fábio Porto-Foresti,&nbsp;Gustavo Akira Toma,&nbsp;Ricardo Utsunomia,&nbsp;Marcelo de Bello Cioffi","doi":"10.1007/s00412-022-00768-1","DOIUrl":"https://doi.org/10.1007/s00412-022-00768-1","url":null,"abstract":"<p><p>Satellites are an abundant source of repetitive DNAs that play an essential role in the chromosomal organization and are tightly linked with the evolution of sex chromosomes. Among fishes, Triportheidae stands out as the only family where almost all species have a homeologous ZZ/ZW sex chromosomes system. While the Z chromosome is typically conserved, the W is always smaller, with variations in size and morphology between species. Here, we report an analysis of the satellitome of Triportheus auritus (TauSat) by integrating genomic and chromosomal data, with a special focus on the highly abundant and female-biased satDNAs. In addition, we investigated the evolutionary trajectories of the ZW sex chromosomes in the Triportheidae family by mapping satDNAs in selected representative species of this family. The satellitome of T. auritus comprised 53 satDNA families of which 24 were also hybridized by FISH. Most satDNAs differed significantly between sexes, with 19 out of 24 being enriched on the W chromosome of T. auritus. The number of satDNAs hybridized into the W chromosomes of T. signatus and T. albus decreased to six and four, respectively, in accordance with the size of their W chromosomes. No TauSat probes produced FISH signals on the chromosomes of Agoniates halecinus. Despite its apparent conservation, our results indicate that each species differs in the satDNA accumulation on the Z chromosome. Minimum spanning trees (MSTs), generated for three satDNA families with different patterns of FISH mapping data, revealed different homogenization rates between the Z and W chromosomes. These results were linked to different levels of recombination between them. The most abundant satDNA family (TauSat01) was exclusively hybridized in the centromeres of all 52 chromosomes of T. auritus, and its putative role in the centromere evolution was also highlighted. Our results identified a high differentiation of both ZW chromosomes regarding satellites composition, highlighting their dynamic role in the sex chromosomes evolution.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"131 1-2","pages":"29-45"},"PeriodicalIF":1.6,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9223702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The N-terminal domain of TET1 promotes the formation of dense chromatin regions refractory to transcription.","authors":"Audrey Lejart,&nbsp;Siham Zentout,&nbsp;Catherine Chapuis,&nbsp;Ostiane D'Augustin,&nbsp;Rebecca Smith,&nbsp;Gilles Salbert,&nbsp;Sébastien Huet","doi":"10.1007/s00412-022-00769-0","DOIUrl":"https://doi.org/10.1007/s00412-022-00769-0","url":null,"abstract":"<p><p>TET (ten-eleven translocation) enzymes initiate active cytosine demethylation via the oxidation of 5-methylcytosine. TET1 is composed of a C-terminal domain, which bears the catalytic activity of the enzyme, and a N-terminal region that is less well characterized except for the CXXC domain responsible for the targeting to CpG islands. While cytosine demethylation induced by TET1 promotes transcription, this protein also interacts with chromatin-regulating factors that rather silence this process, the coordination between these two opposite functions of TET1 being unclear. In the present work, we uncover a new function of the N-terminal part of the TET1 protein in the regulation of the chromatin architecture. This domain of the protein promotes the establishment of a compact chromatin architecture displaying reduced exchange rate of core histones and partial dissociation of the histone linker. This chromatin reorganization process, which does not rely on the CXXC domain, is associated with a global shutdown of transcription and an increase in heterochromatin-associated histone epigenetic marks. Based on these findings, we propose that the dense chromatin organization generated by the N-terminal domain of TET1 could contribute to restraining the transcription enhancement induced by the DNA demethylation activity of this enzyme.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"131 1-2","pages":"47-58"},"PeriodicalIF":1.6,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9231110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Germline-restricted chromosome shows remarkable variation in size among closely related passerine species.","authors":"Manuelita Sotelo-Muñoz,&nbsp;Manon Poignet,&nbsp;Tomáš Albrecht,&nbsp;Ondřej Kauzál,&nbsp;Dmitrij Dedukh,&nbsp;Stephen A Schlebusch,&nbsp;Karel Janko,&nbsp;Radka Reifová","doi":"10.1007/s00412-022-00771-6","DOIUrl":"https://doi.org/10.1007/s00412-022-00771-6","url":null,"abstract":"<p><p>Passerine birds have a supernumerary chromosome in their germ cells called the germline-restricted chromosome (GRC). The GRC was first discovered more than two decades ago in zebra finch but recent studies have suggested that it is likely present in all passerines, the most species rich avian order, encompassing more than half of all modern bird species. Despite its wide taxonomic distribution, studies on this chromosome are still scarce and limited to a few species. Here, we cytogenetically analyzed the GRC in five closely related estrildid finch species of the genus Lonchura. We show that the GRC varies enormously in size, ranging from a tiny micro-chromosome to one of the largest macro-chromosomes in the cell, not only among recently diverged species but also within species and sometimes even between germ cells of a single individual. In Lonchura atricapilla, we also observed variation in GRC copy number among male germ cells of a single individual. Finally, our analysis of hybrids between two Lonchura species with noticeably different GRC size directly supported maternal inheritance of the GRC. Our results reveal the extraordinarily dynamic nature of the GRC, which might be caused by frequent gains and losses of sequences on this chromosome leading to substantial differences in genetic composition of the GRC between and even within species. Such differences might theoretically contribute to reproductive isolation between species and thus accelerate the speciation rate of passerine birds compared to other bird lineages.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"131 1-2","pages":"77-86"},"PeriodicalIF":1.6,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9230411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterologous synapsis in C. elegans is regulated by meiotic double-strand breaks and crossovers.","authors":"Hanwenheng Liu, Spencer G Gordon, Ofer Rog","doi":"10.1007/s00412-021-00763-y","DOIUrl":"10.1007/s00412-021-00763-y","url":null,"abstract":"<p><p>Alignment of the parental chromosomes during meiotic prophase is key to the formation of genetic exchanges, or crossovers, and consequently to the successful production of gametes. In almost all studied organisms, alignment involves synapsis: the assembly of a conserved inter-chromosomal interface called the synaptonemal complex (SC). While the SC usually synapses homologous sequences, it can assemble between heterologous sequences. However, little is known about the regulation of heterologous synapsis. Here, we study the dynamics of heterologous synapsis in the nematode C. elegans. We characterize two experimental scenarios: SC assembly onto a folded-back chromosome that cannot pair with its homologous partner; and synapsis of pseudo-homologs, a fusion chromosome partnering with an unfused chromosome half its size. We observed elevated levels of heterologous synapsis when the number of meiotic double-strand breaks or crossovers were reduced, indicating that the promiscuity of synapsis is regulated by break formation or repair. In addition, our data suggests the existence of both chromosome-specific and nucleus-wide regulation on heterologous synapsis.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"130 4","pages":"237-250"},"PeriodicalIF":2.5,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8671313/pdf/nihms-1755551.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9968422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Allele segregation analysis of F1 hybrids between independent Brassica allohexaploid lineages","authors":"Daniela Quezada-Martinez, J. Zou, Wenshan Zhang, J. Meng, J. Batley, A. Mason","doi":"10.1007/s00412-022-00774-3","DOIUrl":"https://doi.org/10.1007/s00412-022-00774-3","url":null,"abstract":"","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"131 1","pages":"147 - 161"},"PeriodicalIF":1.6,"publicationDate":"2021-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42272705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chromosomal positioning in spermatogenic cells is influenced by chromosomal factors associated with gene activity, bouquet formation and meiotic sex chromosome inactivation.","authors":"M Solé,&nbsp;J Blanco,&nbsp;D Gil,&nbsp;O Valero,&nbsp;Á Pascual,&nbsp;B Cárdenas,&nbsp;G Fonseka,&nbsp;E Anton,&nbsp;R Frodsham,&nbsp;F Vidal,&nbsp;Z Sarrate","doi":"10.1007/s00412-021-00761-0","DOIUrl":"https://doi.org/10.1007/s00412-021-00761-0","url":null,"abstract":"<p><p>Chromosome territoriality is not random along the cell cycle and it is mainly governed by intrinsic chromosome factors and gene expression patterns. Conversely, very few studies have explored the factors that determine chromosome territoriality and its influencing factors during meiosis. In this study, we analysed chromosome positioning in murine spermatogenic cells using three-dimensionally fluorescence in situ hybridization-based methodology, which allows the analysis of the entire karyotype. The main objective of the study was to decipher chromosome positioning in a radial axis (all analysed germ-cell nuclei) and longitudinal axis (only spermatozoa) and to identify the chromosomal factors that regulate such an arrangement. Results demonstrated that the radial positioning of chromosomes during spermatogenesis was cell-type specific and influenced by chromosomal factors associated to gene activity. Chromosomes with specific features that enhance transcription (high GC content, high gene density and high numbers of predicted expressed genes) were preferentially observed in the inner part of the nucleus in virtually all cell types. Moreover, the position of the sex chromosomes was influenced by their transcriptional status, from the periphery of the nucleus when its activity was repressed (pachytene) to a more internal position when it is partially activated (spermatid). At pachytene, chromosome positioning was also influenced by chromosome size due to the bouquet formation. Longitudinal chromosome positioning in the sperm nucleus was not random either, suggesting the importance of ordered longitudinal positioning for the release and activation of the paternal genome after fertilisation.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"130 2-3","pages":"163-175"},"PeriodicalIF":1.6,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00412-021-00761-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39159544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anatomy and evolution of a DNA replication origin.","authors":"Yutaka Yamamoto,&nbsp;Eric A Gustafson,&nbsp;Michael S Foulk,&nbsp;Heidi S Smith,&nbsp;Susan A Gerbi","doi":"10.1007/s00412-021-00756-x","DOIUrl":"https://doi.org/10.1007/s00412-021-00756-x","url":null,"abstract":"<p><p>DNA amplification occurs at the DNA puff II/9A locus in the fungus fly Sciara coprophila. As a foundation to study the molecular mechanism for the initiating events of II/9A DNA re-replication, we have sequenced 14 kb spanning a DNase hypersensitive site (DHS) upstream of the 1 kb amplification origin and through transcription units II/9-1 and II/9-2 downstream of the origin. These elements are annotated as well as the ORC binding site at the origin and the transition point (TP) between continuous and discontinuous DNA syntheses that marks the origin of bidirectional replication at the nucleotide level. A 9 bp motif found at the TP is repeated near the other end of the 1 kb ORI and may identify a putative second TP. The steroid hormone ecdysone induces DNA amplification as well as transcription and puffing at locus II/9A. Within the 14 kb, several matches to the ecdysone response element (EcRE) consensus sequence were identified, including some in the amplification origin region. EcRE O-P is at a central axis of a remarkable symmetry, equidistant to the TPs that are themselves equidistant to EcRE O-1 and EcRE O-2. DNA sequence alterations have occurred throughout the II/9A region in a newly discovered polymorphism (#2). Polymorphism #2 is not specific to developmental stage, sex, or tissue, and it does not impair DNA amplification. The DHS, both 9 bp TP sequences, and EcREs O-1, O-P, and O-2 are conserved between the polymorphism #1 and #2 sequences, suggesting their functional importance and retention during evolutionary selection. Moreover, a 72 bp sequence in the Sciara DHS at DNA puff II/9A is conserved in DNA puff C-3 of Rhynchosciara americana. Comparisons are discussed between the Sciara II/9A amplicon and the chorion locus amplicon on the third chromosome of Drosophila.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"130 2-3","pages":"199-214"},"PeriodicalIF":1.6,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00412-021-00756-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39177883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Trithorax group protein ASH1 requires a combination of BAH domain and AT hooks, but not the SET domain, for mitotic chromatin binding and survival.","authors":"Philipp A Steffen,&nbsp;Christina Altmutter,&nbsp;Eva Dworschak,&nbsp;Sini Junttila,&nbsp;Attila Gyenesei,&nbsp;Xinzhou Zhu,&nbsp;Tobias Kockmann,&nbsp;Leonie Ringrose","doi":"10.1007/s00412-021-00762-z","DOIUrl":"https://doi.org/10.1007/s00412-021-00762-z","url":null,"abstract":"<p><p>The Drosophila Trithorax group (TrxG) protein ASH1 remains associated with mitotic chromatin through mechanisms that are poorly understood. ASH1 dimethylates histone H3 at lysine 36 via its SET domain. Here, we identify domains of the TrxG protein ASH1 that are required for mitotic chromatin attachment in living Drosophila. Quantitative live imaging demonstrates that ASH1 requires AT hooks and the BAH domain but not the SET domain for full chromatin binding in metaphase, and that none of these domains are essential for interphase binding. Genetic experiments show that disruptions of the AT hooks and the BAH domain together, but not deletion of the SET domain alone, are lethal. Transcriptional profiling demonstrates that intact ASH1 AT hooks and the BAH domain are required to maintain expression levels of a specific set of genes, including several involved in cell identity and survival. This study identifies in vivo roles for specific ASH1 domains in mitotic binding, gene regulation, and survival that are distinct from its functions as a histone methyltransferase.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"130 2-3","pages":"215-234"},"PeriodicalIF":1.6,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00412-021-00762-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39268855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sex differences in the meiotic behavior of an XX sex chromosome pair in males and females of the mole vole Ellobius tancrei: turning an X into a Y chromosome?","authors":"Ana Gil-Fernández,&nbsp;Sergey Matveevsky,&nbsp;Marta Martín-Ruiz,&nbsp;Marta Ribagorda,&nbsp;María Teresa Parra,&nbsp;Alberto Viera,&nbsp;Julio S Rufas,&nbsp;Oxana Kolomiets,&nbsp;Irina Bakloushinskaya,&nbsp;Jesús Page","doi":"10.1007/s00412-021-00755-y","DOIUrl":"https://doi.org/10.1007/s00412-021-00755-y","url":null,"abstract":"<p><p>Sex determination in mammals is usually provided by a pair of chromosomes, XX in females and XY in males. Mole voles of the genus Ellobius are exceptions to this rule. In Ellobius tancrei, both males and females have a pair of XX chromosomes that are indistinguishable from each other in somatic cells. Nevertheless, several studies on Ellobius have reported that the two X chromosomes may have a differential organization and behavior during male meiosis. It has not yet been demonstrated if these differences also appear in female meiosis. To test this hypothesis, we have performed a comparative study of chromosome synapsis, recombination, and histone modifications during male and female meiosis in E. tancrei. We observed that synapsis between the two X chromosomes is limited to the short distal (telomeric) regions of the chromosomes in males, leaving the central region completely unsynapsed. This uneven behavior of sex chromosomes during male meiosis is accompanied by structural modifications of one of the X chromosomes, whose axial element tends to appear fragmented, accumulates the heterochromatin mark H3K9me3, and is associated with a specific nuclear body that accumulates epigenetic marks and proteins such as SUMO-1 and centromeric proteins but excludes others such as H3K4me, ubiH2A, and γH2AX. Unexpectedly, sex chromosome synapsis is delayed in female meiosis, leaving the central region unsynapsed during early pachytene. This region accumulates γH2AX up to the stage in which synapsis is completed. However, there are no structural or epigenetic differences similar to those found in males in either of the two X chromosomes. Finally, we observed that recombination in the sex chromosomes is restricted in both sexes. In males, crossover-associated MLH1 foci are located exclusively in the distal regions, indicating incipient differentiation of one of the sex chromosomes into a neo-Y. Notably, in female meiosis, the central region of the X chromosome is also devoid of MLH1 foci, revealing a lack of recombination, possibly due to insufficient homology. Overall, these results reveal new clues about the origin and evolution of sex chromosomes.</p>","PeriodicalId":10248,"journal":{"name":"Chromosoma","volume":"130 2-3","pages":"113-131"},"PeriodicalIF":1.6,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00412-021-00755-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25568621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}