DISSERTATION RESEARCH: A Next-generation Sequencing Approach to the Evolution of Male Reproductive Transcriptomes in Seahorses and Pipefishes

相对于动物和植物基因组编码的大多数蛋白质，那些负责生殖过程的蛋白质在进化过程中变化很快。更具体地说，在生殖组织中表达的蛋白质编码基因通常显示出快速进化的特征。这一趋势目前被认为是交配后性选择的结果，当一种性别的配子为获得另一种性别的配子而竞争时，就会发生这种情况。在海马和管鱼中，雄性在被称为育儿袋的胎盘状生殖组织中养育发育中的后代。在这个鱼类家族中，雌性为获得雄性生殖资源而进行的竞争强度存在很大差异。利用最新的高通量DNA测序技术，研究人员将验证这样一种预测：与交配后性选择较少的物种相比，在交配后性选择激烈的物种中，雄性生殖蛋白进化得更快。这些数据还将揭示雄性生殖角色和雄性育儿袋特有的基因表达模式的进化变化。除了解决中心假设之外，这项工作将为海马和管鱼生物学产生前所未有的DNA序列资源。这些信息将在许多基础和应用环境中发挥作用，包括开发用于保护海马及其近亲的遗传学工具，其中许多海马由于过度捕捞和环境变化而处于危险之中。该项目还将促进与国际科学家的合作，并通过达拉斯世界水族馆向公众宣传。

Relative to the majority of proteins encoded by animal and plant genomes, those responsible for reproductive processes change quickly over evolutionary time. More specifically, protein-coding genes expressed in reproductive tissues routinely show signatures of rapid evolution. This trend is currently thought to arise as a consequence of sexual selection after mating, which occurs when the gametes of one sex compete for access to the gametes of the other sex. In seahorses and pipefishes, males nurture developing offspring in a placenta-like reproductive tissue known as the brood pouch. There is great variation across this family of fishes in the strength of competition among females for access to this male reproductive resource. Using the latest in high-throughput DNA sequencing technologies, the investigators will test the prediction that male reproductive proteins evolve more rapidly in species subject to intense post-mating sexual selection compared to species with little post-mating sexual selection. The data will also shed light on evolutionary changes in patterns of gene expression specific to male reproductive roles and the male's brood pouch. In addition to addressing the central hypothesis, this work will generate an unprecedented number of DNA sequence resources for seahorse and pipefish biology. This information will be useful in many basic and applied contexts, including the development of genetics tools for the conservation of seahorses and their relatives, many of which are imperiled due to over-harvesting and environmental change. The project will also stimulate collaboration with international scientists and public outreach through the the Dallas World Aquarium.