Cis-regulatory diversity and adaptive divergence in the Arabidopsis genus

本项目拟在全基因组水平上研究拟南芥物种间的顺式调控变化。在拟南芥（a.thaliana）与其两个最近的亲缘种（a.lyrata和a.halleri）杂交产生的种间杂交种中，研究了相对等位基因的全基因组表达率。将对经受干旱、寒冷和重金属胁迫的植物叶片的比率进行研究，并将其与未经受干旱、寒冷和重金属胁迫的对照植物叶片的比率进行比较。初步工作强调了表观遗传和表达差异之间的联系。因此，将对亲本基因组进行表观遗传分析，以确定顺式调控变化的突变来源。这个项目的目标有三个：首先，我们想描述自拟南芥属物种形成以来发生的顺式调控变化的程度。其次，我们想要估计特定于环境线索的顺式调控变化的数量，这些环境线索的生态相关性在两个姐妹物种A. lyrata和A. halleri之间是不同的。第三，实验设计的顺式调控变化衍生于A. lyrata或A. halleri谱系可以识别。显示过多顺式调控变化的共调控基因集将精确定位支撑适应性表型分化的基因集合。计划进行实验来验证该方法。如果得到证实，它可以对非模式物种，特别是作物产生重要影响。

This project proposes to examine cis-regulatory changes between Arabidopsis species at a genome-wide level. Relative allele expression ratios will be examined genome-wide in interspecific hybrids generated by crosses between A. thaliana and its two closest relatives, A. lyrata and A. halleri. Ratios will be examined in leaves of plants submitted to drought, cold and heavy metals and compared to ratios observed in leaves of control non challenged plants. Preliminary work has highlighted associations between epigenetic and expression differences. The epigenetic profiling of the parental genomes will therefore be performed in order to ascertain the mutational source of cis-regulatory change. The goal of this project is triple: first we want to describe the extent of cis-regulatory changes that have occurred since speciation in the Arabidopsis genus. Second, we want to estimate the number of cis-regulatory changes that are specific to an environmental cue whose ecological relevance differs between the two sister species A. lyrata and A. halleri. Third, the experiment is designed cis-regulatory changes derived in either the A. lyrata or the A. halleri lineage can be identified. Sets of co-regulated genes displaying an excess of cis-regulatory change will pinpoint gene ensembles underpinning adaptive phenotypic divergence. Experiments are planned to validate this method. If validated, it can have important implications in non-model species, in particular crops.