The genus Boechera(Brassicaceae)serves as a model system for studying apomictic reproduction and ecological adaptations,with most species occurring in North America.The rare occurrence of Boechera species outside thei...The genus Boechera(Brassicaceae)serves as a model system for studying apomictic reproduction and ecological adaptations,with most species occurring in North America.The rare occurrence of Boechera species outside their typical range provides unique opportunities to investigate genome evolution in extralimital environments.One such species,B.calcarea,has been described from the Chandalaz Mountains in northeastern Asia(Russia).This study aimed to investigate the genome structure and evolutionary history of B.calcarea.However,our analyses reveal that the species does not belong to Boechera.Instead,an integrative approach combining cytogenetic,phylogenetic and repeatome analysis identified the species as a member of one of more ancestral clades in the tribe Arabideae.The diploid Parryodes calcarea(2n=16)exhibits Arabideae-specific chromosomal signatures,including multiple centromere repositionings.These findings clarify the misclassification of P.calcarea as Boechera,leaving Boechera falcata and Borodinia macrophylla as the only representatives of the Boechereae in the Old World.This study highlights the importance of an integrative approach in resolving taxonomic ambiguities and provides new insights into the diversification of the largest cruciferous tribe,the Arabideae.展开更多
Centromeres are indispensable for accurate chromosome segregation,but are subject to rapid sequence turnover while maintaining conserved functions--a paradox in genome evolution.To unravel this paradox,we integrated o...Centromeres are indispensable for accurate chromosome segregation,but are subject to rapid sequence turnover while maintaining conserved functions--a paradox in genome evolution.To unravel this paradox,we integrated over 400 fully resolved centromeres from 17 diploid angiosperms spanning 180 million years of divergence,along with 1,000+pan-genomic assemblies,resequencing datasets,and congeneric wholegenome sequences.We showed that angiosperm centromere organization is determined by lineagespecific combinations of satellite repeats and transposable elements(TEs),which,in turn,shape distinct epigenetic landscapes and evolutionary trajectories within centromeres.In particular,TE insertion patterns were found to be key drivers of structural diversification and positional shift of centromeres in angiosperms.Intriguingly,population-level analyses revealed considerable plasticity in centromere sequences across species,with satellite repeats serving as focal points of evolutionary change and exhibiting species-specific heterogeneity patterns.Temporal reconstructions across congeneric species revealed the emergence and subsequent differentiation of centromeric repeats,outlining a dynamic continuum from gradual sequence diversification to complete turnover during speciation,often accompanied by karyotype reorganization.By integrating intra-and inter-species comparisons,we propose a unifying framework in which centromere innovation is governed by a delicate interplay between genome evolution,chromosomal shuffling,and selection constraints,resulting in phylogenomic signatures of centromeredriven speciation.展开更多
基金supported by the Czech Science Foundation(projects 24-11371S to TM and 23-06840S to MAL)Masaryk University Grant Agency(project MUNI/R/1268/2022 to TM)Additional support(PT)was provided as part of a long-term research project of the Czech Academy of Sciences,Institute of Botany(RVO 67985939).
文摘The genus Boechera(Brassicaceae)serves as a model system for studying apomictic reproduction and ecological adaptations,with most species occurring in North America.The rare occurrence of Boechera species outside their typical range provides unique opportunities to investigate genome evolution in extralimital environments.One such species,B.calcarea,has been described from the Chandalaz Mountains in northeastern Asia(Russia).This study aimed to investigate the genome structure and evolutionary history of B.calcarea.However,our analyses reveal that the species does not belong to Boechera.Instead,an integrative approach combining cytogenetic,phylogenetic and repeatome analysis identified the species as a member of one of more ancestral clades in the tribe Arabideae.The diploid Parryodes calcarea(2n=16)exhibits Arabideae-specific chromosomal signatures,including multiple centromere repositionings.These findings clarify the misclassification of P.calcarea as Boechera,leaving Boechera falcata and Borodinia macrophylla as the only representatives of the Boechereae in the Old World.This study highlights the importance of an integrative approach in resolving taxonomic ambiguities and provides new insights into the diversification of the largest cruciferous tribe,the Arabideae.
基金supported by the National Natural Science Foundation of China(32170571 and 32400451)Hubei Provincial Technological Innovation Plan Project(2025BBB014)+2 种基金the project TowArdsNextGENeration Crops(no.CZ.02.01.01/00/22_008/0004581)of the ERDF Programme Johannes Amos ComeniusProject 2662024JC010 was supported by the Fundamental Research Funds for the Central UniversitiesAdditional funding was provided by the Young Top-notch Talent Cultivation Program of Hubei Province and the Natural Science Foundation of Hubei Province of China(2024AFB116).
文摘Centromeres are indispensable for accurate chromosome segregation,but are subject to rapid sequence turnover while maintaining conserved functions--a paradox in genome evolution.To unravel this paradox,we integrated over 400 fully resolved centromeres from 17 diploid angiosperms spanning 180 million years of divergence,along with 1,000+pan-genomic assemblies,resequencing datasets,and congeneric wholegenome sequences.We showed that angiosperm centromere organization is determined by lineagespecific combinations of satellite repeats and transposable elements(TEs),which,in turn,shape distinct epigenetic landscapes and evolutionary trajectories within centromeres.In particular,TE insertion patterns were found to be key drivers of structural diversification and positional shift of centromeres in angiosperms.Intriguingly,population-level analyses revealed considerable plasticity in centromere sequences across species,with satellite repeats serving as focal points of evolutionary change and exhibiting species-specific heterogeneity patterns.Temporal reconstructions across congeneric species revealed the emergence and subsequent differentiation of centromeric repeats,outlining a dynamic continuum from gradual sequence diversification to complete turnover during speciation,often accompanied by karyotype reorganization.By integrating intra-and inter-species comparisons,we propose a unifying framework in which centromere innovation is governed by a delicate interplay between genome evolution,chromosomal shuffling,and selection constraints,resulting in phylogenomic signatures of centromeredriven speciation.
