Evolution of heteromorphic sex chromosomes in Reptilia

爬行动物异形性染色体的进化

• 批准号: 7048519
• 负责人: Daniel E Janes
• 金额: $ 4.6万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7048519
• 关键词: Aves; Chelonia; Crocodilia; Reptilia; artificial chromosomes; biochemical evolution; biotechnology; chickens; developmental genetics; fluorescent in situ hybridization; gene environment interaction; genetic library; genetic mapping; genetic recombination; genetic screening; lizards; nucleic acid sequence; postdoctoral investigator; sex chromosomes; sex determination; sex differentiation; species difference; tissue /cell culture

DESCRIPTION (provided by applicant): The recent creation of bacterial artificial chromosome (BAC) libraries will allow us to sequence and compare portions of sex chromosomes among reptiles and birds. Sex-determining (SD) genes have been found on sex chromosomes in some species and on autosomes in other species. Identification of SD genes consistently found in synteny on either sex chromosomes or autosomes could explain the initiation of sex differentiation in environmentally and genetically SD species. For example, the Sry gene on the Y chromosome initiates sex differentiation in mammals. No Sry homolog has been found in non-mammalian vertebrates. We will use flourescent in situ hybridization and chromosome painting to locate SD genes in representative reptiles and birds. We will compare syntenies of SD genes. Our mapping of SD genes and syntenies will be compared with patterns of heterogamety and SD mechanism. Our broad approach to comparative genomics will allow us to address questions about initiation of sex differentiation in birds and reptiles, genomic differences between species with either genetic or environmental SD mechanisms, causes of chromosomal degeneration, and the history of heteromorphic chromosomes in birds and reptiles.

描述（由申请人提供）：最近创建的细菌人工染色体（BAC）库将使我们能够对爬行动物和鸟类的部分性染色体进行测序和比较。在某些物种的性染色体上和其他物种的常染色体上发现了性别决定（SD）基因。在性染色体或常染色体上一致发现同线性的 SD 基因的鉴定可以解释环境和遗传 SD 物种中性别分化的起始。例如，Y染色体上的Sry基因启动哺乳动物的性别分化。在非哺乳动物脊椎动物中尚未发现 Sry 同源物。我们将利用荧光原位杂交和染色体涂色来定位代表性爬行动物和鸟类的SD基因。我们将比较 SD 基因的同线性。我们对 SD 基因和同线性的图谱将与异配性模式和 SD 机制进行比较。我们的比较基因组学方法将使我们能够解决鸟类和爬行动物性别分化的起始、具有遗传或环境SD机制的物种之间的基因组差异、染色体退化的原因以及鸟类和爬行动物异形染色体的历史等问题。