Genome Repatterning Underlying the Co-evolution of Diploid Number and Gender Determination in Turtles

海龟二倍体数量和性别决定共同进化的基因组重新模式

• 批准号: 1244355
• 负责人: Nicole Valenzuela
• 金额: $ 88.39万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1244355&HistoricalAwards=false
• 关键词: Genome; Repatterning; Underlying; Co; evolution

Gender is determined by genetic constitution in most animals (as by sex XX/XY chromosomes in humans, or ZZ/ZW in birds), and by environmental temperature (TSD) in others, including turtles. Notably, turtle lineages that underwent a transition in the gender-determining mechanism show a 20-fold increase in the rate of evolution of chromosome number, but it is unclear why or how these traits are associated. This project represents the first step to elucidate the functional link between these two traits by testing the hypothesis that chromosomal rearrangements disrupt the location and consequently the regulation of genes controlling sexual development, which in turn cause the transition between gender-determining mechanisms among turtles. By combining molecular cytogenetics, transcriptomics, bioinformatics and phylogenetic analyses, this project will reconstruct the organization of the ancestral turtle genome; characterize the chromosomal rearrangements that have taken place among turtles over 210 million years of turtle evolution; and build mechanistic hypotheses about the critical elements in the regulatory network of sexual development that underlie transitions in gender-determining mechanisms in turtles for further study. This project proposes a novel hypothesis about the relationship of genome evolution over large spans of time and gender determination, which if true, could transform our understanding of the mechanism by which gender determination evolves.Broader ImpactsThe educational activities of this project will help integrate undergraduate discovery-based learning and broaden the participation of underrepresented groups in biology by training students and their mentors; by engaging women and minorities through outreach activities; and by strengthening the PI's qualifications as role model for underrepresented groups.

性别是由大多数动物（如人类中的性XX/XY染色体或鸟类中的ZZ/ZW）以及其他包括乌龟在内的环境温度（TSD）确定的。值得注意的是，在性别定义机制中进行过渡的乌龟谱系显示，染色体数的进化速率增加了20倍，但目前尚不清楚这些性状为什么或如何相关。该项目代表了通过测试染色体重排破坏位置的假设，并因此调节控制性发展的基因的调节，这是阐明这两个性状之间功能联系的第一步，这又导致龟之间性别确定的机制。通过结合分子细胞遗传学，转录组学，生物信息学和系统发育分析，该项目将重建祖先乌龟基因组的组织。表征超过2.1亿年龟进化的海龟中发生的染色体重排；并建立关于性发展监管网络中关键要素的机制假设，这些因素是乌龟中性别确定机制过渡的基础，以进行进一步研究。该项目提出了一个关于基因组进化对大量时间和性别决定的关系的新假设，如果是真的，这可能会改变我们对性别确定能力发展的机制的理解。Broader影响该项目的教育活动将有助于基于发现的研究不足的学习，并通过培训学生及其培训学生的参与来整合基于发现的学习，并扩大其培训学生的参与。通过宣传活动与妇女和少数民族互动；并通过加强PI的资格作为代表性不足的群体的榜样。