Collaborative Research: Genomic Analysis of Dimorphism in Stalk-Eyed Flies (Diopsidae)

该项目旨在确定导致精致男性特征进化的遗传变异。将研究柄眼苍蝇的头部形状，因为这一特征可以表现出极端的性别二型性。在一些物种中，雄性的眼睛被一根比身体还长的柄分开。将确定在眼柄发育过程中表现出性别二态表达的基因和遗传途径，然后将检测几个候选基因的DNA序列变异，以阐明这些基因的功能作用。候选基因将使用微阵列进行选择，这是一项比较两个样本(如男性和女性)之间数千个基因表达的技术。通过比较有或没有二形性眼柄的近亲物种，那些有性二态表达的基因将与眼柄的发育有关。这些基因的功能意义将通过检测序列变异与个体眼柄长度之间的关联来证实。尽管男性和女性的大部分DNA是共同的，但它们在形状和形式上往往表现出巨大的差异。哪些途径造成了这些差异，以及这些途径是如何随着时间的推移而演变的，人们对此知之甚少。这项研究将在整个基因组的水平上，研究与特定的性二型特征相关的基因表达的变异。总体而言，这个项目的结果将提供对选择、性二态进化和DNA变异之间的关系的洞察。

This project aims to identify genetic variation responsible for the evolution of elaborate male traits. Head shape of stalk-eyed flies will be studied because this trait can exhibit extreme sexual dimorphism. In some species the eyes of males are separated by a stalk that is longer than the body. Genes and genetic pathways that exhibit sexually dimorphic expression during eye-stalk development will be identified and then DNA sequence variation at several candidate genes will be examined to elucidate the functional roles of these genes. Candidate genes will be chosen using microarrays, a technology that compares expression of thousands of genes between two samples, such as males and females. Those genes with sexually dimorphic expression will be implicated in eyestalk development by comparing closely related species with or without dimorphic eyestalks. The functional significance of these genes will be confirmed by detecting associations between sequence variation and eyestalk lengths of individuals in a large pedigree.Despite having most of their DNA in common, males and females often exhibit dramatic differences in shape and form. Which pathways create these differences and how these pathways evolve over time is poorly understood. This research will examine, at the level of the entire genome, variation in gene expression associated with a specific sexually dimorphic character. Overall, the results from this project will provide insight into the relationships between selection, the evolution of sexual dimorphism and DNA variation.