Dissertation Research: Molecular Phylogenetic Analysis of the Major Lineages of Tapeworms (Platyhelminthes: Eucestoda)

9701052 CAIRA绦虫是专性扁虫寄生虫，通常局限于特定的宿主动物。许多绦虫物种已经与它们的宿主有很长一段时间的联系。了解绦虫的系统发育历史对生物学家来说意义重大，他们希望了解宿主和寄生虫物种共同历史的后果，并减少绦虫对人类和家养动物的有害影响。由于形态特征少且难以解释，化石缺失，分子特征研究尚未开展，绦虫的系统发育史一直难以重建。在本研究中，Janine Caira、Chris Simon和博士生Peter Olson将通过对绦虫14个主要类群（目）中代表性物种的核编码18s样核糖体RNA基因进行测序，推断绦虫的系统发育历史，并对这些序列进行比较分析。这项工作将为检验基于形态学、生态学和其他类型证据的绦虫系统发生历史假设提供基础。特别是，研究人员将确定在一个目中的绦虫是否有共同的历史（是单系群so）。

9701052 CAIRA Tapeworms are obligate flatworm parasites that are often restricted to specific host animals. Many tapeworm species have been associated with their hosts for long periods of time. Understanding the phylogenetic history of tapeworms is significant to biologists, who wish to understand the consequences of shared history on host and parasite species, and to lessen the harmful effects of tapeworms on humans and domesticated animals. The phylogenetic history of tapeworms has been difficult to reconstruct, because morphological characters are few and difficult to interpret, fossils are absent, and investigations on molecular characters have not been conducted. In this research, Janine Caira, Chris Simon and doctoral candidate Peter Olson will infer the phylogenetic history of tapeworms by sequencing the nucleus-encoded 18S-like ribosomal RNA gene, from representative species in each of 14 recognized major groups (orders) of tapeworms, and conducting a comparative analysis of these sequences. The work will provide a foundation with which to test hypotheses of tapeworm phylogenetic history based on morphological, ecological, and other types of evidence. In particular, the researchers will determine whether the tapeworms placed within an order share a common history (are Omonophyletic groupsO) or not.