第357回 平成29年12月8日
(第236回 遺伝子機能解析部門セミナー)

演題「DNA replication-coupled histone modification maintains Polycomb gene silencing in plants」
(植物におけるDNA複製に共役的なヒストン修飾によるポリコーム遺伝子サイレンシングの維持)

Frédéric Berger 氏 (Gregor Mendel Institute, Austrian Academy of Sciences, Vienna, Austria)
 
  Propagation of patterns of gene expression through the cell cycle requires prompt restoration of epigenetic marks after the twofold dilution caused by DNA replication. Here, we show that the transcriptional repressive mark histone H3 lysine 27 trimethylation (H3K27me3) is restored in replicating plant cells through DNA replication-coupled modification of histone variant H3.1. Plants evolved a mechanism for efficient K27 trimethylation on H3.1, which is essential for inheritance of the silencing memory from mother to daughter cells. We illustrate how this mechanism establishes H3K27me3 mediated silencing during the developmental transition to flowering. Our study reveals a mechanism responsible for transmission of H3K27me3 in plant cells through cell divisions, enabling H3K27me3 to function as an epigenetic mark.

Danhua Jiang and Frédéric Berger.
Science 2017 Sep 15;357(6356):1146-1149.
doi: 10.1126/science.aan4965. Epub 2017 Aug 17.

 遺伝子発現のエピジェネティック制御のひとつにヒストンのメチル化修飾によるクロマチン構造の変化があります。植物の花成(成長相の転換)における細胞分裂のDNA複製時に、その修飾がどのように維持され、遺伝子の転写制御が行われているのか、植物のエピジェネティック制御の仕組みの最新知見について講述頂きます。(演者記)