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

9701052凯纳绦虫是专性扁虫寄生虫，通常仅限于特定的宿主动物。许多绦虫物种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具有重要意义，他们希望了解共同的历史对宿主和寄生虫物种的影响，并减少绦虫对人类和家养动物的有害影响。绦虫的系统发育历史一直很难重建，因为形态特征很少，很难解释，缺乏化石，也没有对分子特征的研究。在这项研究中，Janine Casa、Chris Simon和博士生Peter Olson将从14个公认的绦虫主要类群(目)中的每个代表性物种中测序18S样核糖体RNA基因，并对这些序列进行比较分析，从而推断绦虫的系统发育历史。这项工作将为检验基于形态、生态和其他类型证据的绦虫系统发育历史假说提供基础。特别是，研究人员将确定在一个目中放置的绦虫是否具有共同的历史(是单系类群O)。

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.