报告题目：Harnessing the Power of Next-Generation Genetics:The Plant Immune System at the Nexus of Trade-Offs Affecting Fitness and Gene Flow

报告人： Prof. Detlef Weigel，Max Planck Institute for Developmental Biology, Tübingen, Germany

报告时间：2011年4月11日，上午9:00-10:30

报告地点：B210报告厅

联系人： 李家洋

联系电话：64852855

Abstract

To understand how species-wide sequence variation translates into phenotypic variation, we are employing bottom-up (i.e., forward genetic) and top-down (i.e., whole-genome) approaches, both of which rely heavily on second-generation sequencing. Whole-genome sequencing not only supports a detailed description of the pan-genome of Arabidopsis thaliana (Clark et al., Science 2007; Ossowski et al., Genome Research 2008; Nordborg & Weigel, Nature 2009; http://1001genomes.org), but it has also revealed mutational biases that shape the genome (Ossowski et al., Science 2010). In addition, it allows for rapid mapping of genetic variants with major phenotypic effects (Schneeberger et al., Nature Methods 2009).

A major interest is the analysis of reproductive barriers that may ultimately lead to speciation. A few years ago, we developed A. thaliana as a model for the study of hybrid necrosis, a widespread syndrome of hybrid failure in plants (Bomblies et al., PLoS Biology 2007). In the affected hybrids, a specific gene product contributed by one of the parents is inappropriately recognized as foreign and pathogenic, leading to massive cell death and ultimate demise of the plant. We have cloned the causal genes for several incompatibilities in Arabidopsis thaliana. Some of the lessons that we have learned are that autoimmune reactions can be caused by interaction of two R proteins, and that not all R genes are equally likely to give rise to incompatibilities. Sometimes alleles at a single locus, ACD6, can inappropriately activate the immune system, and this gene has also alleles that are responsible for a major fitness tradeoff between growth and pathogen resistance in inbred strains (Todesco et al., Nature 2010). We propose that evolutionary divergence of pathogen recognition systems can potentially result in reproductive isolation and subsequent speciation, not only by random genetic drift, but also by divergent selection due to different pathogen environments.