Systematics and Evolution of Nematode Family Rhabditidae

david H. fitch博士。纽约大学的大卫·h·费奇（David H. Fitch）获得了一项资助，用于研究横纹线虫科物种之间的进化关系。栖息地的多样性和丰富程度使横纹肌科成为一个重要的分类群，但它在生物多样性、系统发育和进化方面是最不为人所知的动物类群之一。最近的证据表明，一些农业上重要的寄生虫起源于横纹肌科，这提高了这些原本“自由生活”的线虫对寄生虫起源研究或指导与寄生虫密切相关的自由生活模式的研究的重要性。此外，该家族还包括秀丽隐杆线虫，它被用作发育遗传学的模型，使该物种成为地球上研究最多的动物之一。需要一个系统发育来检验这个模型的普遍性，并从秀丽隐杆线虫到其他横纹肌科和其他后生动物系统中引导基因组功能的信息。系统发育还需要测试形式和行为之间可能的相关性，例如雄性尾巴形态的进化变化和雄性交配行为之间的关系。这种相关性可能提供了洞察可能的前适应和选择模式，导致横纹肌形式的多样性。形态学和分子数据将用于推断横纹肌科的系统发育。从最近的发育和超微结构研究中得出的强有力的同源性标准将用于形态学特征的分析，例如雄性交配囊（“雄性尾巴”）的特征。所有已知的（和一些尚未描述的）分类群的形态数据将与著名的横纹虫动物学家沃尔特·苏德豪斯（柏林自由大学）合作汇编。分子数据将收集至少两个已知的在这个分类水平上具有系统发育信息的位点，18S核糖体RNA基因的几乎完整序列和RNA聚合酶II位点的部分序列。初步数据表明，所有三个数据分区提供了一致的系统发育信息，从而允许“全证据”的方法来重建横纹肌系统发育。

DEB-9981632David H. FitchDr. David H. Fitch at New York University has been awarded a grant to study the evolutionary relationships among species in the nematode family Rhabditidae. Habitat diversity and sheer abundance alone make Rhabditidae an important taxon, yet it is one of the most poorly understood animal groups in terms of biodiversity, phylogeny and evolution. Recent evidence suggests that some agriculturally important parasites arose within Rhabditidae, elevating the importance of these otherwise "free-living" nematodes for research on the origins of parasites or directing searches for free-living models closely related to parasites. Moreover, the family includes Caenorhabditis elegans, whose use as a model in developmental genetics has made that species one of the most intensively studied animals on Earth. A phylogeny is required to test generalizations from this model and to bootstrap information on genome functionality from C. elegans to other Rhabditidae and other metazoan systems. The phylogeny will also be required to test possible correlations between form and behavior, such as those between evolutionary changes in male tail morphology and male copulatory behavior. Such correlations may to provide insight into possible preadaptations and modes of selection resulting in the diversity of rhabditid forms.Morphological and molecular data will be used to infer a phylogeny for Rhabditidae. Robust homology criteria derived from recent developmental and ultrastructural studies will be used in the analysis of morphological characters, such as features of the male copulatory bursa ("male tail"). Morphological data for all known (and some still-undescribed) taxa will be compiled in a collaboration with renowned rhabditid zoologist Walter Sudhaus (Freie Universitat Berlin). Molecular data will be collected for at least two loci known to be phylogenetically informative at this taxonomic level, nearly complete sequences of 18S ribosomal RNA genes and partial sequences from the RNA Polymerase II locus. Preliminary data suggest that all three data partitions provide congruent phylogenetic information, thus allowing a "total evidence" approach to reconstruct rhabditid phylogeny.