Baldwin J G, Frisse L M, Vida J T, Eddleman C D, Thomas W K
Department of Nematology, University of California, Riverside, California 92521, USA.
Mol Phylogenet Evol. 1997 Oct;8(2):249-59. doi: 10.1006/mpev.1997.0433.
Nematodes are known to be a useful system for studies of comparative development. Here we perform a molecular phylogenetic analysis to allow for the independent interpretation of the developmental and morphological changes observed among a selected set of nematode species. Our molecular phylogenetic analysis is based on coding regions of the genes for RNA polymerase II, the small subunit rRNA and an expansion segment of the large subunit rRNA. Sequences were compared from five species in the family (Rhabditidae) that includes the developmental model organism Caenorhabditis elegans and from an outgroup taxon Aduncospiculum halicti (Diplogasterina). The phylogenetic analysis does not support the monophyly of the subfamily Mesorhabditinae and identifies the unnamed strain PS1010 as a sister taxon of C. elegans despite its morphologically divergent buccal capsule. On the basis of the inferred framework, we can begin to interpret the evolution of vulval development and of morphological differences among these nematode species.
线虫是用于比较发育研究的有用系统。在此，我们进行了分子系统发育分析，以便独立解释在一组选定的线虫物种中观察到的发育和形态变化。我们的分子系统发育分析基于RNA聚合酶II、小亚基rRNA和大亚基rRNA的一个扩展片段的基因编码区。比较了包括发育模式生物秀丽隐杆线虫在内的小杆线虫科五个物种的序列，以及一个外类群分类单元Aduncospiculum halicti（双胃线虫亚目）的序列。系统发育分析不支持中杆线虫亚科的单系性，并确定未命名的PS1010菌株是秀丽隐杆线虫的姐妹分类单元，尽管其口囊在形态上存在差异。基于推断的框架，我们可以开始解释这些线虫物种外阴发育的进化以及形态差异。
