Drosophila Seminal Fluid: Proteomic Discovery & Functional Variation Analyses

描述(申请人提供)：这项提案有两个主要方面，重点是生殖基因的功能和进化。首先，我们将使用一种新的蛋白质组学方法来鉴定在各种果蝇物种交配过程中从雄性转移到雌性的精液成分。这种方法将利用十二个果蝇基因组测序项目的基因组数据，从而能够研究这些基因的进化动力学。我们期待找到适应性进化的证据。此外，我们希望发现动态的基因获得/丢失。从这些分析中，我们将深入了解一类独特的生殖蛋白的进化。基因组测序项目中的一个常见发现是生殖基因的快速进化。然而，这些基因通常只根据组织表达或间接证据被预测参与生殖。通过将我们的蛋白质组数据与基因组资源相结合，我们将拥有一组独特的生殖基因来研究这一普遍观察。我们建议的第二个方面是利用序列数据和定量质谱学来研究这些基因的功能分化。果蝇精液与精子竞争的许多方面有关。此外，这些性状在种群内存在可遗传的遗传变异。然而，精液基因与精子竞争表型之间的关系尚未见报道。我们将利用克隆方法从异种繁殖的种群中产生半克隆雄性果蝇，并对这些果蝇进行精子竞争力极端尾巴的筛选。将分析这些品系的精液基因序列变异和每个精液蛋白的转移量。后者是一种新的方法，它直接测量相关的生物学特性(转移到雌性果蝇身上的蛋白质数量)，而不是典型的测量雄性果蝇转录本丰度的方法。 与公共健康相关：基因组测序项目一再发现，生殖基因是包括人类在内的各种生物中差异最大的基因。对生殖和受精的完整分子理解需要研究为什么这些基因进化得如此之快。虽然这项研究的重点是果蝇，但在灵长类动物的精液中也观察到了类似类别的基因和进化动态。因此，这里的结果可能会为灵长类生殖生物学提供深入的见解。

DESCRIPTION (provided by applicant): This proposal has two main aspects, focused on the function and evolution of reproductive genes. First, we will use a novel proteomics approach to identify the seminal fluid components that are transferred from males to females during mating in a variety of Drosophila species. This approach will utilize the genomic data from the twelve Drosophila genomes sequencing project, allowing for the investigation of the evolutionary dynamics of these genes. We anticipate finding evidence for adaptive evolution. Additionally, we expect to uncover dynamic gene gain/loss. From these analyses, we will gain insights into the evolution of a unique class of reproductive proteins. A common finding in genome sequencing projects is the rapid evolution of reproductive genes. However, these genes are usually predicted to be involved in reproduction based only upon tissue expression or indirect evidence. By combining our proteomic data with genomic resources, we will have a unique set of reproductive genes to investigate this general observation. The second aspect of our proposal is to investigate the functional differentiation of these genes, using both sequence data and quantitative mass spectrometry. Drosophila seminal fluid is implicated in many aspects of sperm competition. Additionally, heritable genetic variation exists within populations for these traits. However, few associations between seminal fluid genes and sperm competition phenotype have been reported. We will utilize a clonal method to generate hemiclonal males from an outbred population and screen these flies for the extreme tails of sperm competitiveness. These lines will be analyzed for both seminal fluid gene sequence variation and quantity of each seminal fluid protein transferred. The latter is a novel approach and directly measures the relevant biological trait (quantity of protein transferred to females), rather than the typical approach of measuring transcript abundance in male flies. Relevance to public health: Genome sequencing projects repeatedly find reproductive genes to be the most divergent genes from a wide variety of organisms, including humans. A complete molecular understanding of reproduction and fertilization requires investigation into why these genes are evolving so rapidly. While the proposal focuses on Drosophila, similar classes of genes and evolutionary dynamics have been observed in primate seminal fluid. Therefore, the results here may provide insights into primate reproductive biology.