Rhizoglyphus robini genome sequencing, assembly and resequencing of laboratory evolved populations

The purpose of the project was to fill the important gap in our understanding of the process of evolution by checking if evolution of elaborated, sexually selected traits does help to maintain genetic variation within populations. The project used experimental evolution approach, and the subject of evolution in laboratory was bulb mite, in which males vary in expression of elaborated sexually selected trait: thickened legs which are costly to produce and hinder movement but are useful in intersexual combats. Populations were forced to evolve towards low or high proportion of males with thickened legs, and after 30 generations (about 2 year in laboratory) their genomes were sequenced to check whether amount of genetic variation is higher in evolutionary lines in which thickened legs are common. Prior to that we sequenced and assembled reference genome of the bulb mite.

本项目旨在填补当前对演化过程认知中的重要空白，通过验证经性选择演化形成的复杂性状是否有助于维持种群内的遗传变异，开展相关研究。本项目采用实验演化（experimental evolution）研究方法，实验演化的模式生物为球螨（bulb mite）：该物种的雄性个体在性选择相关复杂性状的表达上存在差异——特化的加厚腿部，其发育成本高昂且会阻碍运动，但在两性争斗中具备实用价值。研究人员将种群人为导向两个演化方向：高比例携带加厚腿部的雄性种群，以及低比例携带加厚腿部的雄性种群。经过30代演化（实验室条件下耗时约2年）后，对各演化系的基因组进行测序，以验证在加厚腿部雄性较为常见的演化系谱中，遗传变异总量是否更高。在此之前，本团队已完成球螨参考基因组（reference genome）的测序与组装工作。