RUI: Understanding the role of duplicate Hox genes in the evolution of novelty by investigating patterns of molecular evolution and functional divergence in a basal ray-finned fish

进化生物学中最有趣的话题之一是什么类型的遗传变化负责产生表型多样性的问题。该项目将验证的中心假设是，基因复制在脊椎动物新特征的进化中发挥了重要作用，更具体地说，在白鲟的长喙中。美洲白鲟生活在密西西比河流域浑浊的水域中，它的喙部很长，这是一种夸张的新颖特征，具有电感觉能力。这种具有魅力的生物属于一个具有动态基因组复制历史的目，数据表明在白鲟中发生了独立的基因组复制。基因复制被认为是具有新功能和相关表型新颖性的基因产生的主要机制，但促进重复基因初始保留的进化过程尚未得到很好的理解。一个被称为Hox基因的基因家族与身体形状特征的进化有关。然而，以往关于鱼喙和鳍发育过程中Hox基因表达的研究并没有考虑到这一点。本项目将研究白鲟中重复Hox基因的分子进化和功能分化的各个方面。这项提议的工作意义重大，因为它通过在最多样化的脊椎动物群体——鳍状鱼类中维持重复基因，确定了与新结构进化相关的遗传途径。这项工作具有重要而广泛的影响，因为它有助于在旧金山州立大学培训代表性不足的少数族裔和女性学生，这是一所主要的本科院校，为大量少数族裔学生提供服务。此外，这项研究的结果将被注入到旧金山州立大学的本科课程。

One of the most intriguing topics in evolutionary biology is the question of what types of genetic changes are responsible for generating phenotypic diversity. The central hypothesis that will be tested in this project is that gene duplication has played an important role in the evolution of novel features in vertebrates, more specifically in the elongated rostrum in the paddlefish. The American paddlefish makes its living in the murky waters of the Mississippi River Basin with its elongated rostrum - an exaggerated novel feature with electrosensory capabilities. This charismatic organism belongs to an order with a dynamic genome duplication history, and data indicate that an independent genome duplication occurred in paddlefish. Gene duplication is regarded as the predominant mechanism by which genes with new functions and associated phenotypic novelties arise, but the evolutionary processes contributing to the initial retention of duplicate genes are not well understood. A family of genes called Hox genes have been implicated in the evolution of body plan features. However previous studies on Hox gene expression during rostrum and fin development in fish have not taken this into account. This project will examine various aspects of the molecular evolution and functional divergence of duplicated Hox genes in paddlefish. The proposed work is significant because it identifies genetic pathways associated with the evolution of novel structures, via maintenance of duplicate genes in the most diverse vertebrate group, ray-finned fishes. This work has important and broad impacts because it contributes to the training of underrepresented minority and female students at San Francisco State University, a primarily undergraduate institution that serves large numbers of minority students. In addition, the results of this research will be infused into the undergraduate curricula at San Francisco State.