2022年8月4日出版的《科学》杂志发表了捷克科学家的一项最新研究成果。来自
据研究人员介绍，减数分裂，在二倍体和单倍体生命周期阶段之间的过渡，伴随着细胞分裂机制的重新编程，随后过渡到有丝分裂。
研究人员表明，在拟南芥中，这种转变是由翻译的抑制所驱动的，是通过一种涉及加工小体（P小体）的机制实现的。在减数第二次分裂期间，减数分裂特异性蛋白THREE-DIVISION MUTANT 1（TDM1）通过与SUPPRESSOR WITH MORPHENETIC EFFECTS ON GENITALIA 7（SMG7）相互作用被纳入P小体。TDM1吸引eIF4F，即主要的翻译起始复合物，暂时将其封存在P小体中并抑制翻译。TDM1突变体终止减数分裂的失败可以通过化学抑制翻译来克服。研究人员提出，含有TDM1的P小体下调减数分裂转录本的表达，从而促进细胞命运向减数分裂后配子体分化的过渡。
附：英文原文
Title: Meiotic exit in Arabidopsis is driven by P-body–mediated inhibition of translation
Author: Albert Cairo, Anna Vargova, Neha Shukla, Claudio Capitao, Pavlina Mikulkova, Sona Valuchova, Jana Pecinkova, Petra Bulankova, Karel Riha
Issue&Volume: 2022-08-05
Abstract: Meiosis, at the transition between diploid and haploid life cycle phases, is accompanied by reprograming of cell division machinery and followed by a transition back to mitosis. We show that, in Arabidopsis, this transition is driven by inhibition of translation, achieved by a mechanism that involves processing bodies (P-bodies). During the second meiotic division, the meiosis-specific protein THREE-DIVISION MUTANT 1 (TDM1) is incorporated into P-bodies through interaction with SUPPRESSOR WITH MORPHOGENETIC EFFECTS ON GENITALIA 7 (SMG7). TDM1 attracts eIF4F, the main translation initiation complex, temporarily sequestering it in P-bodies and inhibiting translation. The failure of tdm1 mutants to terminate meiosis can be overcome by chemical inhibition of translation. We propose that TDM1-containing P-bodies down-regulate expression of meiotic transcripts to facilitate transition of cell fates to postmeiotic gametophyte differentiation.
DOI: abo0904
Source: https://www.science.org/doi/10.1126/science.abo0904