Dissertation Research: Evolution of Outcrossing and Sex Ratio in Caenorhabditis elegans

本研究旨在从进化和生态学的角度对模式生物秀丽隐杆线虫进行研究。 在这种线虫中，雌雄同体--具有雄性/雌性生殖器官的个体--可以单独繁殖，也可以通过受精从雄性身上繁殖。本研究旨在阐明雄性在该物种中的作用，并探索异交进化中的一般特征。特别是：什么最接近和ultimateforces影响男性的能力，坚持，在什么频率？这些问题将通过（1）利用分子生物学方法确定雄性在大型实验室和自然群体中的频率，（2）进行实验室选择实验以检验维持异交的假设来解决。优雅这个物种已经从遗传学（第一个动物基因组测序）和发育生物学（受精卵和成年人之间的所有细胞命运）进行了深入的研究，但是关于它的生态学和其不寻常的繁殖系统的进化过程的信息不成比例地少。本研究将整合多种互补的方法，以更好地描述该模式生物的生态学和进化，并对进化研究中与进化和异交维持相关的一般问题产生影响。

This research aims to impart an evolutionary and ecological perspective onthe study of a model organism, the nematode Caenorhabditis elegans. In thisnematode, hermaphrodites--individuals with male/female reproductive organs--mayreproduce alone or via fertilization from males. This research seeks to elucidatethe role of males in this species and to explore general features involvedin the evolution of outcrossing. In particular: what proximate and ultimateforces influence the ability of males to persist, and at what frequencies? These issues will be addressed by (1) using molecular methods to determinethe frequency of males in large lab and natural populations, and (2) performinglab selection experiments to test hypotheses for the maintenance of outcrossing.This work will provide one of the first evolutionary ecological perspectivesfor C. elegans. This species has been subject to intensive study from genetics(the first animal genome sequenced) and developmental biology (all cell fatesare mapped between zygote and adult), but disproportionately little informationis available regarding its ecology and the processes underlying the evolutionof its unusual breeding system. This research will integrate multiple complementaryapproaches to characterize a more resonant description of ecology and evolutionin this model organism, and bear on general issues in the study of evolutionrelating to the evolution and maintenance of outcrossing.