讲座主题：Sequestration of a transposon-derived siRNA by a target mimic imprinted gene induces postzygotic reproductive isolation in Arabidopsis

专家姓名： 王桂凤

工作单位：河南农业大学

讲座时间：2018.7.22上午9:30

讲座地点：海院329

主办单位：烟台大学海洋学院

内容摘要：

Genomic imprinting is an epigenetic phenomenon occurring in mammals and flowering plants causing genes to be expressed depending on their parent-of-origin. In plants, genomic imprinting is mainly confined to the endosperm, a nutritive tissue supporting embryo growth, similar to the placenta in mammals. Here we show that the paternally expressed imprinted gene PEG2 transcript is a small RNA sponge and sequesters the transposable element-derived small interfering RNA siRNA854 in the endosperm. SiRNA854 is present in the vegetative cell of pollen and transferred to the central cell of the female gametophyte after fertilization, where it is captured by PEG2. Depletion of siRNA854 as a consequence of increased PEG2 transcript levels establishes a reproductive barrier and prevents successful hybridizations between plants differing in chromosome number (ploidy). Thus, the balance of a male gamete accumulating TE-derived siRNA and a paternally-expressed imprinted gene regulate triploid seed viability, revealing a transgenerational epigenetic speciation mechanism.

主讲人介绍：

王桂凤，教授，博士生导师，省部共建小麦玉米作物学国家重点实验室玉米籽粒研究方向的学术带头人。2008年博士毕业于南京林业大学，随后受聘上海大学生命科学学院从事玉米分子遗传学研究；2014年至2016年在瑞典农业大学Claudia Köhler院士实验室从事拟南芥种子发育的表观遗传调控研究；2017年11月作为特聘教授引进到河南农业大学农学院工作；2009年江苏省优秀博士论文获得者，2017年获得上海市浦江人才计划，2018年获得河南省科技创新杰出青年。主要从事玉米和拟南芥胚和胚乳发育的遗传和表观遗传调控，倍性间及种属间生殖障碍的分子机制研究。主持国家级项目3项，省部级项目5项。以第一作者（或者共同一作）或通讯作者在Developmental Cell, Plant Cell, New Phytologist, Plant Biotechnology Journal和Journal of Experimental Botany等学术杂志上发表SCI论文多篇。