第1503回生物科学セミナー
Molecular determinants of transgenerational epigenetic variation at transposable element sequences in Arabidopsis and its impact in nature
Vincent Colot（Ecole Normale Supérieure）
2024年07月01日(月) 13:30-15:00 理学部2号館講堂
Transposable element (TE) sequences are targeted by epigenetic mechanisms, which include DNA methylation in plants and mammals. In plants, this chromatin modification is not extensively reset at every generation, opening up the possibility of TE-associated transgenerational epigenetic inheritance (TEI). However, the determinants, prevalence, and phenotypic consequences of TEI in nature remain unclear. Based on comprehensive analyses of DNA methylation in epigenetic recombinant inbred lines as well as in hundreds of strains of Arabidopsis thaliana, we identified ~1000 TE sequences with instances of severe hypomethylation in nature. Two main antagonistic genomic forces shape such natural epivariation: trans RNA-directed DNA methylation and nearby Pol-II activity, which limits and facilitates the possibility of TEI at a given TE sequence, respectively. Crucially, most natural TE epivariants are truly epiallelic. Furthermore, they are enriched near stress-responsive genes, where they can enhance their induction and thus may be targets of selection. Collectively, these findings establish the significance and limits of natural TEI in plants.
担当： 東京大学大学院理学系研究科・生物科学専攻・遺伝学研究室
