The dynamic activity of transposable elements(TEs)contributes to the vast diversity of genome size and architecture among plants.Here,we examined the genomic distribution and transposition activity of long terminal re...The dynamic activity of transposable elements(TEs)contributes to the vast diversity of genome size and architecture among plants.Here,we examined the genomic distribution and transposition activity of long terminal repeat retrotransposons(LTR-RTs)in Arabidopsis thaliana(Ath)and three of its relatives,Arabidopsis lyrata(Aly),Eutrema salsugineum(Esa),and Schrenkiella parvula(Spa),in Brassicaceae.Our analyses revealed the distinct evolutionary dynamics of Gypsy retrotransposons,which reflects the different patterns of genome size changes of the four species over the past million years.The rate of Gypsy transposition in Aly is approximately five times more rapid than that of Ath and Esa,suggesting an expanding Aly genome.Gypsy insertions in Esa are strictly confined to pericentromeric heterochromatin and associated with dramatic centromere expansion.In contrast,Gypsy insertions in Spa have been largely suppressed over the last million years,likely as a result of a combination of an inherent molecular mechanism of preferential DNA removal and purifying selection at Gypsy elements.Additionally,species-specific clades of Gypsy elements shaped the distinct genome architectures of Aly and Esa.展开更多
Eukaryotic genomes are compacted into histone-wrapped chromatin,which provides an opportunity to fine-tune the gene expression by dynamically impeding or reinforcing the accessibility of the genome to the transcriptio...Eukaryotic genomes are compacted into histone-wrapped chromatin,which provides an opportunity to fine-tune the gene expression by dynamically impeding or reinforcing the accessibility of the genome to the transcription factors(TFs)and cofactors.The modification of histones is one of the various mechanisms to regulate DNA exposure by altering the physical properties of nucleosomes(Klemm et al.,2019).In plants,histone modifications play a critical role in establishing the cell identity and responding to environmental cues,including responses to temperature,alterations of flowering time(Liu et al.,2010;He et al.,2021).展开更多
基金the“Innovation Project for the Postdoctoral Researchers”in Chinathe“Open Research Fund Program”of Beijing Key Lab of Plant Resource Research and Development,Beijing Technology and Business University。
文摘The dynamic activity of transposable elements(TEs)contributes to the vast diversity of genome size and architecture among plants.Here,we examined the genomic distribution and transposition activity of long terminal repeat retrotransposons(LTR-RTs)in Arabidopsis thaliana(Ath)and three of its relatives,Arabidopsis lyrata(Aly),Eutrema salsugineum(Esa),and Schrenkiella parvula(Spa),in Brassicaceae.Our analyses revealed the distinct evolutionary dynamics of Gypsy retrotransposons,which reflects the different patterns of genome size changes of the four species over the past million years.The rate of Gypsy transposition in Aly is approximately five times more rapid than that of Ath and Esa,suggesting an expanding Aly genome.Gypsy insertions in Esa are strictly confined to pericentromeric heterochromatin and associated with dramatic centromere expansion.In contrast,Gypsy insertions in Spa have been largely suppressed over the last million years,likely as a result of a combination of an inherent molecular mechanism of preferential DNA removal and purifying selection at Gypsy elements.Additionally,species-specific clades of Gypsy elements shaped the distinct genome architectures of Aly and Esa.
基金supported by the National Natural Science Foundation of China(31670321)the fund of Northwest A&F University(Z111021404)the Talents Program of Shaanxi Province of China。
文摘Eukaryotic genomes are compacted into histone-wrapped chromatin,which provides an opportunity to fine-tune the gene expression by dynamically impeding or reinforcing the accessibility of the genome to the transcription factors(TFs)and cofactors.The modification of histones is one of the various mechanisms to regulate DNA exposure by altering the physical properties of nucleosomes(Klemm et al.,2019).In plants,histone modifications play a critical role in establishing the cell identity and responding to environmental cues,including responses to temperature,alterations of flowering time(Liu et al.,2010;He et al.,2021).
