Pub Date : 2022-12-01DOI: 10.1007/s10577-022-09690-9
Kai Wang, Hon Cheng, Jinlei Han, Ayman Esh, Jiayong Liu, Yuebin Zhang, Baohua Wang
{"title":"Correction to: A comprehensive molecular cytogenetic analysis of the genome architecture in modern sugarcane cultivars.","authors":"Kai Wang, Hon Cheng, Jinlei Han, Ayman Esh, Jiayong Liu, Yuebin Zhang, Baohua Wang","doi":"10.1007/s10577-022-09690-9","DOIUrl":"https://doi.org/10.1007/s10577-022-09690-9","url":null,"abstract":"","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10774455","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}
Pub Date : 2022-12-01DOI: 10.1007/s10577-022-09709-1
James R Paulson, Erica R Vander Mause, Elizabeth Dillinger, Megan E Luedeman, Bakhtawar Usman
Histones H1 and H3 are highly phosphorylated in mitotic HeLa cells but are rapidly dephosphorylated by endogenous protein phosphatases during the isolation of metaphase chromosomes. We show that this dephosphorylation can be prevented by including the sulfhydryl reagent 5,5'-dithiobis-(2-nitrobenzoate) (Ellman's reagent, or DTNB) in the isolation buffer. The minimal amount of DTNB required is approximately stoichiometric with the number of sulfhydryl groups in the lysate. Inhibition of the protein phosphatases can subsequently be reversed by treatment with dithiothreitol or 2-mercaptoethanol. DTNB is compatible with the isolation of either metaphase chromosome clusters or individual metaphase chromosomes. It should be useful in investigations of the structure and biochemistry of chromatin and chromosomes and in the study of possible functions for mitotic histone phosphorylation.
{"title":"Ellman's reagent prevents dephosphorylation of histones during isolation of mitotic chromosomes.","authors":"James R Paulson, Erica R Vander Mause, Elizabeth Dillinger, Megan E Luedeman, Bakhtawar Usman","doi":"10.1007/s10577-022-09709-1","DOIUrl":"https://doi.org/10.1007/s10577-022-09709-1","url":null,"abstract":"<p><p>Histones H1 and H3 are highly phosphorylated in mitotic HeLa cells but are rapidly dephosphorylated by endogenous protein phosphatases during the isolation of metaphase chromosomes. We show that this dephosphorylation can be prevented by including the sulfhydryl reagent 5,5'-dithiobis-(2-nitrobenzoate) (Ellman's reagent, or DTNB) in the isolation buffer. The minimal amount of DTNB required is approximately stoichiometric with the number of sulfhydryl groups in the lysate. Inhibition of the protein phosphatases can subsequently be reversed by treatment with dithiothreitol or 2-mercaptoethanol. DTNB is compatible with the isolation of either metaphase chromosome clusters or individual metaphase chromosomes. It should be useful in investigations of the structure and biochemistry of chromatin and chromosomes and in the study of possible functions for mitotic histone phosphorylation.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10626855","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}
Pub Date : 2022-12-01DOI: 10.1007/s10577-022-09699-0
Shivangi Nath, Lucille A Welch, Mary K Flanagan, Michael A White
Double-strand break repair during meiosis is normally achieved using the homologous chromosome as a repair template. Heteromorphic sex chromosomes share little sequence homology, presenting unique challenges to the repair of double-strand breaks. Our understanding of how heteromorphic sex chromosomes behave during meiosis has been focused on ancient sex chromosomes, where the X and Y differ markedly in overall structure and gene content. It remains unclear how more recently evolved sex chromosomes that share considerably more sequence homology with one another pair and form double-strand breaks. One possibility is barriers to pairing evolve rapidly. Alternatively, recently evolved sex chromosomes may exhibit pairing and double-strand break repair that more closely resembles that of their autosomal ancestors. Here, we use the recently evolved X and Y chromosomes of the threespine stickleback fish (Gasterosteus aculeatus) to study patterns of pairing and double-stranded break formation using molecular cytogenetics. We found that the sex chromosomes of threespine stickleback fish did not pair exclusively in the pseudoautosomal region. Instead, the chromosomes fully paired in a non-homologous fashion. To achieve this, the X chromosome underwent synaptic adjustment during pachytene to match the axis length of the Y chromosome. Double-strand break formation and repair rate also matched that of the autosomes. Our results highlight that recently evolved sex chromosomes exhibit meiotic behavior that is reminiscent of autosomes and argues for further work to identify the homologous templates that are used to repair double-strand breaks on the X and Y chromosomes.
{"title":"Meiotic pairing and double-strand break formation along the heteromorphic threespine stickleback sex chromosomes.","authors":"Shivangi Nath, Lucille A Welch, Mary K Flanagan, Michael A White","doi":"10.1007/s10577-022-09699-0","DOIUrl":"https://doi.org/10.1007/s10577-022-09699-0","url":null,"abstract":"<p><p>Double-strand break repair during meiosis is normally achieved using the homologous chromosome as a repair template. Heteromorphic sex chromosomes share little sequence homology, presenting unique challenges to the repair of double-strand breaks. Our understanding of how heteromorphic sex chromosomes behave during meiosis has been focused on ancient sex chromosomes, where the X and Y differ markedly in overall structure and gene content. It remains unclear how more recently evolved sex chromosomes that share considerably more sequence homology with one another pair and form double-strand breaks. One possibility is barriers to pairing evolve rapidly. Alternatively, recently evolved sex chromosomes may exhibit pairing and double-strand break repair that more closely resembles that of their autosomal ancestors. Here, we use the recently evolved X and Y chromosomes of the threespine stickleback fish (Gasterosteus aculeatus) to study patterns of pairing and double-stranded break formation using molecular cytogenetics. We found that the sex chromosomes of threespine stickleback fish did not pair exclusively in the pseudoautosomal region. Instead, the chromosomes fully paired in a non-homologous fashion. To achieve this, the X chromosome underwent synaptic adjustment during pachytene to match the axis length of the Y chromosome. Double-strand break formation and repair rate also matched that of the autosomes. Our results highlight that recently evolved sex chromosomes exhibit meiotic behavior that is reminiscent of autosomes and argues for further work to identify the homologous templates that are used to repair double-strand breaks on the X and Y chromosomes.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10570487","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}
Pub Date : 2022-12-01DOI: 10.1007/s10577-022-09702-8
Claudio Montenegro, Lívia do Vale Martins, Fernanda de Oliveira Bustamante, Ana Christina Brasileiro-Vidal, Andrea Pedrosa-Harand
The tribe Phaseoleae includes several legume crops with assembled genomes. Comparative genomic studies have evidenced the preservation of large genomic blocks among legumes, although chromosome dynamics during Phaseoleae evolution has not been investigated. We conducted a comparative genomic analysis to define an informative genomic block (GB) system and to reconstruct the ancestral Phaseoleae karyotype (APK). We identified GBs based on the orthologous genes between Phaseolus vulgaris and Vigna unguiculata and searched for GBs in different genomes of the Phaseolinae (P. lunatus) and Glycininae (Amphicarpaea edgeworthii) subtribes and Spatholobus suberectus (sister to Phaseolinae and Glycininae), using Medicago truncatula as the outgroup. We also used oligo-FISH probes of two P. vulgaris chromosomes to paint the orthologous chromosomes of two non-sequenced Phaseolinae species. We inferred the APK as having n = 11 and 19 GBs (A to S), hypothesizing five chromosome fusions that reduced the ancestral legume karyotype to n = 11. We identified the rearrangements among the APK and the subtribes and species, with extensive centromere repositioning in Phaseolus. We also reconstructed the chromosome number reduction in S. suberectus. The development of the GB system and the proposed APK provide useful approaches for future comparative genomic analyses of legume species.
{"title":"Comparative cytogenomics reveals genome reshuffling and centromere repositioning in the legume tribe Phaseoleae.","authors":"Claudio Montenegro, Lívia do Vale Martins, Fernanda de Oliveira Bustamante, Ana Christina Brasileiro-Vidal, Andrea Pedrosa-Harand","doi":"10.1007/s10577-022-09702-8","DOIUrl":"https://doi.org/10.1007/s10577-022-09702-8","url":null,"abstract":"<p><p>The tribe Phaseoleae includes several legume crops with assembled genomes. Comparative genomic studies have evidenced the preservation of large genomic blocks among legumes, although chromosome dynamics during Phaseoleae evolution has not been investigated. We conducted a comparative genomic analysis to define an informative genomic block (GB) system and to reconstruct the ancestral Phaseoleae karyotype (APK). We identified GBs based on the orthologous genes between Phaseolus vulgaris and Vigna unguiculata and searched for GBs in different genomes of the Phaseolinae (P. lunatus) and Glycininae (Amphicarpaea edgeworthii) subtribes and Spatholobus suberectus (sister to Phaseolinae and Glycininae), using Medicago truncatula as the outgroup. We also used oligo-FISH probes of two P. vulgaris chromosomes to paint the orthologous chromosomes of two non-sequenced Phaseolinae species. We inferred the APK as having n = 11 and 19 GBs (A to S), hypothesizing five chromosome fusions that reduced the ancestral legume karyotype to n = 11. We identified the rearrangements among the APK and the subtribes and species, with extensive centromere repositioning in Phaseolus. We also reconstructed the chromosome number reduction in S. suberectus. The development of the GB system and the proposed APK provide useful approaches for future comparative genomic analyses of legume species.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10570900","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}
Pub Date : 2022-12-01DOI: 10.1007/s10577-022-09706-4
Alexander I Shevchenko, Nikita A Rifel, Suren M Zakian, Irina S Zakharova
Imprinted X chromosome inactivation (iXCI) balances the expression of X-linked genes in preimplantation embryos and extraembryonic tissues in rodents. Long noncoding Xist RNA drives iXCI, silencing genes and recruiting Xist-dependent chromatin repressors. Some domains on the inactive X chromosome include repressive modifications specific to constitutive heterochromatin, which show no direct link to Xist RNA. We explored the relationship between Xist RNA and chromatin silencing during iXCI in vole Microtus levis. We performed locus-specific activation of Xist transcription on the only active X chromosome using the dCas9-SAM system in XO vole trophoblast stem cells (TSCs), which allow modeling iXCI events to some extent. The artificially activated endogenous vole Xist transcript is truncated and restricted ~ 6.6 kb of the exon 1. Ectopic Xist RNA accumulates on the X chromosome and recruits Xist-dependent modifications during TSC differentiation, yet is incapable by itself repressing X-linked genes. Transcriptional silencing occurs upon ectopic Xist upregulation only when repressive marks spread from the massive telomeric constitutive heterochromatin to the X chromosome region containing genes. We hypothesize that the Xist RNA-induced propagation of repressive marks from the constitutive heterochromatin could be a mechanism involved in X chromosome inactivation.
{"title":"Constitutive heterochromatin propagation contributes to the X chromosome inactivation.","authors":"Alexander I Shevchenko, Nikita A Rifel, Suren M Zakian, Irina S Zakharova","doi":"10.1007/s10577-022-09706-4","DOIUrl":"https://doi.org/10.1007/s10577-022-09706-4","url":null,"abstract":"<p><p>Imprinted X chromosome inactivation (iXCI) balances the expression of X-linked genes in preimplantation embryos and extraembryonic tissues in rodents. Long noncoding Xist RNA drives iXCI, silencing genes and recruiting Xist-dependent chromatin repressors. Some domains on the inactive X chromosome include repressive modifications specific to constitutive heterochromatin, which show no direct link to Xist RNA. We explored the relationship between Xist RNA and chromatin silencing during iXCI in vole Microtus levis. We performed locus-specific activation of Xist transcription on the only active X chromosome using the dCas9-SAM system in XO vole trophoblast stem cells (TSCs), which allow modeling iXCI events to some extent. The artificially activated endogenous vole Xist transcript is truncated and restricted ~ 6.6 kb of the exon 1. Ectopic Xist RNA accumulates on the X chromosome and recruits Xist-dependent modifications during TSC differentiation, yet is incapable by itself repressing X-linked genes. Transcriptional silencing occurs upon ectopic Xist upregulation only when repressive marks spread from the massive telomeric constitutive heterochromatin to the X chromosome region containing genes. We hypothesize that the Xist RNA-induced propagation of repressive marks from the constitutive heterochromatin could be a mechanism involved in X chromosome inactivation.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10574899","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}
Pub Date : 2022-12-01DOI: 10.1007/s10577-022-09694-5
Menghan Li, Shuyue Li, Yan He, Yan Wang, Ting Zhang, Ping Li, Yan He
Most plant species have three or more SPO11/TOPOVIA homologs and two TOPOVIB homologs, which associate to trigger meiotic double-strand break (DSB) formation and subsequent meiotic recombination. In Zea mays L. (maize), ZmSPO11-1 and ZmMTOPVIB have been reported to be indispensable for the initiation of meiotic recombination, yet the function of ZmSPO11-2 remains unclear. In this study, we characterized meiotic functions of ZmSPO11-2 during male meiosis in maize. Two independent Zmspo11-1 knock-out mutants exhibited normal vegetative growth but both male and female sterility. The formation of meiotic DSBs of DNA molecules was fully abolished in the Zmspo11-2 plants, leading to the defective homologous chromosome paring, synapsis, recombination, and segregation. However, the bipolar spindle assembly was not noticeably affected in Zmspo11-2 meiocytes. Overall, our results demonstrate that as its partner ZmSPO11-1 and ZmMTOPVIB, ZmSPO11-2 plays essential roles in DSB formation and homologous recombination in maize meiosis.
{"title":"ZmSPO11-2 is critical for meiotic recombination in maize.","authors":"Menghan Li, Shuyue Li, Yan He, Yan Wang, Ting Zhang, Ping Li, Yan He","doi":"10.1007/s10577-022-09694-5","DOIUrl":"https://doi.org/10.1007/s10577-022-09694-5","url":null,"abstract":"<p><p>Most plant species have three or more SPO11/TOPOVIA homologs and two TOPOVIB homologs, which associate to trigger meiotic double-strand break (DSB) formation and subsequent meiotic recombination. In Zea mays L. (maize), ZmSPO11-1 and ZmMTOPVIB have been reported to be indispensable for the initiation of meiotic recombination, yet the function of ZmSPO11-2 remains unclear. In this study, we characterized meiotic functions of ZmSPO11-2 during male meiosis in maize. Two independent Zmspo11-1 knock-out mutants exhibited normal vegetative growth but both male and female sterility. The formation of meiotic DSBs of DNA molecules was fully abolished in the Zmspo11-2 plants, leading to the defective homologous chromosome paring, synapsis, recombination, and segregation. However, the bipolar spindle assembly was not noticeably affected in Zmspo11-2 meiocytes. Overall, our results demonstrate that as its partner ZmSPO11-1 and ZmMTOPVIB, ZmSPO11-2 plays essential roles in DSB formation and homologous recombination in maize meiosis.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10570895","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}
Pub Date : 2022-12-01DOI: 10.1007/s10577-021-09679-w
Tatyana D Kolesnikova, Galina V Pokholkova, Viktoria V Dovgan, Igor F Zhimulev, Veit Schubert
Studying the probability distribution of replication initiation along a chromosome is a huge challenge. Drosophila polytene chromosomes in combination with super-resolution microscopy provide a unique opportunity for analyzing the probabilistic nature of replication initiation at the ultrastructural level. Here, we developed a method for synchronizing S-phase induction among salivary gland cells. An analysis of the replication label distribution in the first minutes of S phase and in the following hours after the induction revealed the dynamics of replication initiation. Spatial super-resolution structured illumination microscopy allowed identifying multiple discrete replication signals and to investigate the behavior of replication signals in the first minutes of the S phase at the ultrastructural level. We identified replication initiation zones where initiation occurs stochastically. These zones differ significantly in the probability of replication initiation per time unit. There are zones in which initiation occurs on most strands of the polytene chromosome in a few minutes. In other zones, the initiation on all strands takes several hours. Compact bands are free of replication initiation events, and the replication runs from outer edges to the middle, where band shapes may alter.
{"title":"Super-resolution microscopy reveals stochastic initiation of replication in Drosophila polytene chromosomes.","authors":"Tatyana D Kolesnikova, Galina V Pokholkova, Viktoria V Dovgan, Igor F Zhimulev, Veit Schubert","doi":"10.1007/s10577-021-09679-w","DOIUrl":"https://doi.org/10.1007/s10577-021-09679-w","url":null,"abstract":"<p><p>Studying the probability distribution of replication initiation along a chromosome is a huge challenge. Drosophila polytene chromosomes in combination with super-resolution microscopy provide a unique opportunity for analyzing the probabilistic nature of replication initiation at the ultrastructural level. Here, we developed a method for synchronizing S-phase induction among salivary gland cells. An analysis of the replication label distribution in the first minutes of S phase and in the following hours after the induction revealed the dynamics of replication initiation. Spatial super-resolution structured illumination microscopy allowed identifying multiple discrete replication signals and to investigate the behavior of replication signals in the first minutes of the S phase at the ultrastructural level. We identified replication initiation zones where initiation occurs stochastically. These zones differ significantly in the probability of replication initiation per time unit. There are zones in which initiation occurs on most strands of the polytene chromosome in a few minutes. In other zones, the initiation on all strands takes several hours. Compact bands are free of replication initiation events, and the replication runs from outer edges to the middle, where band shapes may alter.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9771856/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10569347","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}
Pub Date : 2022-12-01Epub Date: 2022-12-02DOI: 10.1007/s10577-022-09708-2
Dmitrij Dedukh, Irene da Cruz, Susanne Kneitz, Anatolie Marta, Jenny Ormanns, Tomáš Tichopád, Yuan Lu, Manfred Alsheimer, Karel Janko, Manfred Schartl
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.
产生克隆后代的单性繁殖是有性繁殖的另一种策略,甚至在脊椎动物中也会出现。人们已经描述了多种非有性生殖模式,其中最不为人所知的一个问题是这种途径是如何出现的,以及它们是如何从机理上进行的。亚马逊鲂(Poecilia formosa)需要来自相关物种雄性的精子来触发二倍体卵子的孤雌生殖发育。然而,未还原的雌配子是如何产生的,其机制仍不清楚。细胞学分析表明,初级卵母细胞的染色体启动了pachytene,但没有进行二价形成和减数分裂交叉。比较 P. formosa 和其有性亲本的卵巢转录组发现,减数分裂特异性基因的表达水平与 P. mexicana 不同,但与 P. latipinna 不同。此外,一些减数分裂基因的表达偏向于亲本基因组的两个等位基因之一。我们从我们的数据中推断,在亚马逊小骡子中,二倍体卵母细胞是由于同源染色体的突触失败而通过无性繁殖产生的。这种失败并没有反映在已知减数分裂基因的差异表达上,这一事实表明其潜在的分子机制可能是蛋白质水平的失调或迄今未知的减数分裂基因的错误表达,以及/或由于来自不同基因组的蛋白质相互作用受损而导致的杂交育种不良。
{"title":"Achiasmatic meiosis in the unisexual Amazon molly, Poecilia formosa.","authors":"Dmitrij Dedukh, Irene da Cruz, Susanne Kneitz, Anatolie Marta, Jenny Ormanns, Tomáš Tichopád, Yuan Lu, Manfred Alsheimer, Karel Janko, Manfred Schartl","doi":"10.1007/s10577-022-09708-2","DOIUrl":"10.1007/s10577-022-09708-2","url":null,"abstract":"<p><p>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.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9771850/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9123336","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}
Pub Date : 2022-12-01DOI: 10.1007/s10577-022-09704-6
Anastassia Boudichevskaia, Anne Fiebig, Katrin Kumke, Axel Himmelbach, Andreas Houben
The B chromosome (B) is a dispensable component of the genome in many species. To evaluate the impact of Bs on the transcriptome of the standard A chromosomes (A), comparative RNA-seq analyses of rye and wheat anthers with and without additional rye Bs were conducted. In both species, 5-6% of the A-derived transcripts across the entire genomes were differentially expressed in the presence of 2Bs. The GO term enrichment analysis revealed that Bs influence A chromosome encoded processes like "gene silencing"; "DNA methylation or demethylation"; "chromatin silencing"; "negative regulation of gene expression, epigenetic"; "post-embryonic development"; and "chromosome organization." 244 B chromosome responsive A-located genes in + 2B rye and + B wheat shared the same biological function. Positively correlated with the number of Bs, 939 and 1391 B-specific transcripts were identified in + 2B and + 4B wheat samples, respectively. 85% of B-transcripts in + 2B were also found in + 4B transcriptomes. 297 B-specific transcripts were identified in + 2B rye, and 27% were common to the B-derived transcripts identified in + B wheat. Bs encode mobile elements and housekeeping genes, but most B-transcripts were without detectable similarity to known genes. Some of these genes are involved in cell division-related functions like Nuf2 and might indicate their importance in maintaining Bs. The transcriptome analysis provides new insights into the complex interrelationship between standard A chromosomes and supernumerary B chromosomes.
{"title":"Rye B chromosomes differently influence the expression of A chromosome-encoded genes depending on the host species.","authors":"Anastassia Boudichevskaia, Anne Fiebig, Katrin Kumke, Axel Himmelbach, Andreas Houben","doi":"10.1007/s10577-022-09704-6","DOIUrl":"https://doi.org/10.1007/s10577-022-09704-6","url":null,"abstract":"<p><p>The B chromosome (B) is a dispensable component of the genome in many species. To evaluate the impact of Bs on the transcriptome of the standard A chromosomes (A), comparative RNA-seq analyses of rye and wheat anthers with and without additional rye Bs were conducted. In both species, 5-6% of the A-derived transcripts across the entire genomes were differentially expressed in the presence of 2Bs. The GO term enrichment analysis revealed that Bs influence A chromosome encoded processes like \"gene silencing\"; \"DNA methylation or demethylation\"; \"chromatin silencing\"; \"negative regulation of gene expression, epigenetic\"; \"post-embryonic development\"; and \"chromosome organization.\" 244 B chromosome responsive A-located genes in + 2B rye and + B wheat shared the same biological function. Positively correlated with the number of Bs, 939 and 1391 B-specific transcripts were identified in + 2B and + 4B wheat samples, respectively. 85% of B-transcripts in + 2B were also found in + 4B transcriptomes. 297 B-specific transcripts were identified in + 2B rye, and 27% were common to the B-derived transcripts identified in + B wheat. Bs encode mobile elements and housekeeping genes, but most B-transcripts were without detectable similarity to known genes. Some of these genes are involved in cell division-related functions like Nuf2 and might indicate their importance in maintaining Bs. The transcriptome analysis provides new insights into the complex interrelationship between standard A chromosomes and supernumerary B chromosomes.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9771852/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10568641","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}
Pub Date : 2022-09-01Epub Date: 2022-07-06DOI: 10.1007/s10577-022-09701-9
Susan A Gerbi
Mendelian inheritance is based upon random segregation of homologous chromosomes during meiosis and perfect duplication and division of chromosomes in mitosis so that the entire genomic content is passed down to the daughter cells. The unusual chromosome mechanics of the fly Bradysia (previously called Sciara) presents many exceptions to the canonical processes. In male meiosis I, there is a monopolar spindle and non-random segregation such that all the paternal homologs move away from the single pole and are eliminated. In male meiosis II, there is a bipolar spindle and segregation of the sister chromatids except for the X dyad that undergoes non-disjunction. The daughter cell that is nullo-X degenerates, whereas the sperm has two copies of the X. Fertilization restores the diploid state, but there are three copies of the X chromosome, of which one or two of the paternally derived X chromosomes will be eliminated in an early cleavage division. Bradysia (Sciara) coprophila also has germ line limited L chromosomes that are eliminated from the soma. Current information and the molecular mechanisms for chromosome imprinting and eliminations, which are just beginning to be studied, will be reviewed here.
孟德尔遗传的基础是同源染色体在减数分裂过程中的随机分离,以及染色体在有丝分裂过程中的完美复制和分裂,从而使整个基因组内容传递给子细胞。苍蝇 Bradysia(以前称为 Sciara)的染色体机械结构不同寻常,它的典型过程有许多例外。在雄性减数分裂 I 中,存在单极纺锤体和非随机分离,所有父系同源染色体都远离单极并被淘汰。在雄性减数分裂 II 中,出现双极纺锤体和姐妹染色单体的分离,但 X 染色体不发生分离。受精后会恢复二倍体状态,但 X 染色体有三个拷贝,其中一个或两个父源 X 染色体会在早期裂殖分裂中被消除。Bradysia (Sciara) coprophila 也具有种系限制的 L 染色体,这些染色体会从体细胞中消除。本文将对染色体印记和消除的现有信息和分子机制进行综述,这些研究刚刚起步。
{"title":"Non-random chromosome segregation and chromosome eliminations in the fly Bradysia (Sciara).","authors":"Susan A Gerbi","doi":"10.1007/s10577-022-09701-9","DOIUrl":"10.1007/s10577-022-09701-9","url":null,"abstract":"<p><p>Mendelian inheritance is based upon random segregation of homologous chromosomes during meiosis and perfect duplication and division of chromosomes in mitosis so that the entire genomic content is passed down to the daughter cells. The unusual chromosome mechanics of the fly Bradysia (previously called Sciara) presents many exceptions to the canonical processes. In male meiosis I, there is a monopolar spindle and non-random segregation such that all the paternal homologs move away from the single pole and are eliminated. In male meiosis II, there is a bipolar spindle and segregation of the sister chromatids except for the X dyad that undergoes non-disjunction. The daughter cell that is nullo-X degenerates, whereas the sperm has two copies of the X. Fertilization restores the diploid state, but there are three copies of the X chromosome, of which one or two of the paternally derived X chromosomes will be eliminated in an early cleavage division. Bradysia (Sciara) coprophila also has germ line limited L chromosomes that are eliminated from the soma. Current information and the molecular mechanisms for chromosome imprinting and eliminations, which are just beginning to be studied, will be reviewed here.</p>","PeriodicalId":50698,"journal":{"name":"Chromosome Research","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10777868/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40566499","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}