Dissertation Research: Phylogenetic Inference from Bryozoan Hox Genes

该项目将研究苔藓虫的进化起源，苔藓虫是一组水生动物，有许多物种通过无性繁殖形成殖民地。尽管苔藓虫与软体动物、环节动物和其他原生动物类群的关联得到了很好的支持，但这些类群之间的关系却不是。然而，有数据表明苔藓虫从一个共同的祖先分化而来，比其他的栉虫纲成员更有吸引力，值得进一步研究。本研究将研究Hox基因，这是早期发育中重要的转录因子。Hox基因的DNA序列，以及它们在基因组中的排列，在动物进化的过程中一直是保守的，使它们成为理解广泛不同动物群体之间关系的良好候选者。我们将利用DNA测序和基因定位来研究苔藓虫的两个主要分支——舌口虫和层甲虫的Hox基因。这些数据将与其他信息相结合，以推断苔藓虫和其他主要动物谱系之间的关系。本研究的结果将为动物发育和身体结构的早期进化提供重要信息。此外，苔藓虫Hox基因的测序和定位将为未来研究苔藓虫群体中动物多态性的起源提供一个平台。

This project will investigate the evolutionary origin of bryozoans, a group of aquatic animals with many species that form colonies by asexual reproduction. Although association of bryozoans with molluscs, annelids, and other protostome taxa is well supported, relationships among these groups is not. Data suggesting that bryozoans diverged from a common ancestor before other members of the clade Lophotrochozoa is, however, intriguing and warrants further investigation. The present study will investigate Hox genes, which are important transcription factors in early development. The DNA sequence of Hox genes, as well as their arrangement within the genome, has been conserved over the course of animal evolution, making them good candidates for understanding relationships between widely divergent groups of animals. DNA sequencing and gene mapping will be utilized to investigate the Hox genes of representatives from two major lineages of bryozoans, cheilostomes and phylactolaemates. These data will be combined with other information to infer the relationships between bryozoans and other major lineages of animals.Results of this study will provide important information concerning the early evolution of animal development and body plans. Additionally, the sequencing and mapping of bryozoan Hox genes will provide a platform for future work on the origins of zooid polymorphism in bryozoan colonies.