Evolution of Male Tail Development in Rhabditid Nematodes Related to Caenorhabditis Elegans

The evolutionary pathway that has led to male tails of diverse morphology among species of the nematode family Rhabditidae was reconstructed. This family includes the well-studied model species Caenorhabditis elegans. By relating the steps of male tail morphological evolution to the phenotypic changes brought about by developmental mutations induced experimentally in C. elegans, the goal is to identify genes responsible for morphological evolution. The varying morphological characters of the male tails of several rhabditid species have been described previously (Fitch and Emmons, 1995, Dev. Biol. 170:564--582). The developmental events preceding differentiation of the adult structures have also been analyzed; in many cases the origins of varying adult morphological characters were traced to differences during ontogeny. In the present work, the evolutionary changes producing these differences were reconstructed in the context of the four possible phylogenies supported independently by se...

本研究重建了杆形线虫科（Rhabditidae）内各物种雄性尾部形态多样性的演化路径。该类群包含被学界广泛研究的模式物种秀丽隐杆线虫（Caenorhabditis elegans）。研究通过将雄性尾部形态演化的各个阶段，与实验诱导秀丽隐杆线虫产生的发育突变所对应的表型变化建立关联，旨在识别驱动形态演化的关键基因。此前已有研究对数种杆形线虫的雄性尾部多样化形态特征进行了描述（Fitch与Emmons，1995，《发育生物学》（Dev. Biol.）170:564–582）。此外，学界还对成虫结构分化前的发育事件开展了分析：在多数案例中，成虫形态特征的差异起源可追溯至个体发育过程中的差异。本研究则在四项经独立数据支撑的系统发育树（phylogeny）框架下，对造成上述发育差异的演化变化进行了重建——