Evolutionary genomics of new Drosophila genes

描述(申请人提供)：比较基因组学揭示了真核生物基因组包含许多孤儿基因--仅限于特定进化谱系的基因。其中一些是具有新组织和功能的新基因。这些新基因是如何起源和确立的，这是塑造基因组进化的一个重要但鲜为人知的现象。这个项目的目的是利用12个密切相关的果蝇物种(年龄在300Ky-40My)的全基因组序列来识别新的基因，并表征它们的分子起源和进化。计算方法将被用来识别许多新的基因，并将它们的起源(或缺失)映射到已知的果蝇系统发育。然后，将使用分子和群体遗传学方法，从基因表达模式和历史证据中验证这些新基因的子集的功能，以纯化和/或正选择DNA多态和分化模式。这项工作将提供新基因进化起源的完整图景，重要的是，有助于对所有调查的基因组进行完整的功能注释。开发的方法将适用于其他基因组的比较分析，包括人类及其灵长类亲属的基因组。

DESCRIPTION (provided by applicant): Comparative genomics has revealed that eukaryotic genomes harbor many orphan genes-- genes restricted to particular evolutionary lineages. Some of these are new genes with novel organizations and functions. How these new genes originate and become established is an important but poorly understood phenomenon shaping genome evolution. The aim of this project is to use whole genome sequences from 12 closely related Drosophila species (aged 300 Ky - 40 My) to identify new genes and characterize their molecular origin and evolution. Computational methods will be used to identify many new genes and map their origin (or loss) onto the known Drosophila phylogeny. Molecular and population genetics methods will then be used to validate function for a subset of these new genes from patterns of gene expression and from historical evidence for purifying and/or positive selection in patterns of DNA polymorphism and divergence. This work will provide a full portrait of the evolutionary origin of new genes and, importantly, contribute to the complete functional annotation of all the genomes surveyed. The methods developed will be applicable in comparative analysis of other genomes, including those of humans and their primate relatives.