"Gene Trafficking on an Evolving X Chromosome in Drosophila"

“果蝇进化 X 染色体上的基因贩运”

• 批准号: 8231546
• 负责人: Doris Bachtrog
• 金额: $ 29.21万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8231546
• 关键词: Alternative Splicing; Base Sequence; Computer Analysis; Data; Defect; Dosage Compensation (Genetics); Drosophila genus; Evolution; Fertility; Gene Duplication; Gene Expression; Gene Expression Profile; Genes; Genetic; Genetic Polymorphism; Genome; Genomics; Head; Human; Larva; Location; Male Infertility; Modeling; Molecular; Molecular Profiling; Movement; Ovary; Pattern; Population; Population Genetics; Property; RNA; Relative (related person); Sex Bias; Sex Chromosomes; System; Testing; Testis; Tissues; X Chromosome; X Inactivation; Y Chromosome; autosome; comparative; comparative genomics; driving force; duplicate genes; fly; functional genomics; genome sequencing; genome-wide; improved; male; novel; pressure; response; sample fixation; sex; trafficking; transcriptomics

Genes are distributed non-randomly across the genome. One intriguing pattern to emerge from genome-wide expression profiling is that genes with sex-biased expression that is, genes that are differentially expressed between the sexes show a biased distribution on sex chromosomes. In particular, male-biased genes are depleted from the Drosophila X chromosome, such that the X has become demasculinized. The deficiency of male-biased genes can partly be explained by movement of male genes off the X chromosome. The evolutionary forces underlying these patterns are controversial and may involve male germline X inactivation, sexual antagonism, or dosage compensation mechanisms. Drosophila miranda - a species for which we recently generated a de novo genome sequence assembly - has a newly formed sex chromosome system. Its neo-Y chromosome is in transition from an ordinary autosome to a degenerate Y. In response, the neo-X is evolving the stereotypical properties of a differentiated X, including the acquisition of partial dosage compensation and - as suggested by preliminary data - an excess of gene translocations originating from its neo-X. D. Miranda therefore provides a unique system to study the mechanisms of gene trafficking on an evolving X chromosome and its evolutionary causes in action using a comparative and functional genomics approach.

基因在基因组中非随机分布。全基因组表达谱中出现的一个有趣的模式是，具有性别偏向表达的基因，即在两性之间差异表达的基因在性染色体上表现出偏向分布。特别是，果蝇 X 染色体中偏雄性的基因被耗尽，使得 X 变得去男性化。男性基因的缺乏可以部分解释为男性基因离开X染色体。这些模式背后的进化力量是有争议的，可能涉及雄性生殖系 X 失活、性对抗或剂量补偿机制。米兰达果蝇——我们最近为其生成了从头基因组序列组装的物种——具有新形成的性染色体系统。它的 neo-Y 染色体正在从普通常染色体转变为简并 Y。作为回应，neo-X 正在进化出分化 X 的刻板特性，包括获得部分剂量补偿，以及（如初步数据所示）源自 Neo-X 的过量基因易位。因此，D. Miranda 提供了一个独特的系统，使用比较和功能基因组学方法来研究进化 X 染色体上的基因贩运机制及其进化原因。