DISSERTATION RESEARCH: Possible evolution of a novel ZW chromosome system in a hybrid laboratory population of the copepod Tigriopus californicus

论文研究：桡足类 Tigriopus californicus 实验室杂交群体中新型 ZW 染色体系统的可能进化

• 批准号: 1406366
• 负责人: Suzanne Edmands
• 金额: $ 2万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1406366&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Possible; evolution; novel

Among sexually reproducing organisms, the allocation of maleness and femaleness to offspring occurs in many ways, most familiarly, via sex chromosomes (XX females and XY males in humans, flies; ZW females and ZZ males in birds, butterflies). Although closely-related species often differ in their sex determination mechanisms, why those evolve is poorly understood. The marine crustacean Tigriopus californicus has many genetically isolated populations and polygenic (genetic, but non-chromosomal) sex determination. Previous work with a laboratory-created hybrid population revealed that females, but not males, are often heterozygous across an entire chromosome (bearing one copy from each original population), suggesting that it could be acting as a Z/W sex chromosome. This project will use next-generation DNA sequencing on individuals from this hybrid population and its wild progenitors to identify identify the sex determination mechanism in each population and to ascertain whether the hybrid population has evolved a novel sex chromosome.This project investigates the genetic basis of sex determination in copepods, one of the most abundant animal groups on the planet. Sex chromosomes are a predictable outcome of evolution. The emergence of a sex chromosome in a hybrid population would suggest that sex determination mechanism switches could be a consequence of hybridization-induced genomic disruption. This is especially important in light of the increasing hybridization occurring in natural populations due to human-driven processes, such as species introductions and climate change-induced range shifts. In addition, the project will include extensive mentoring of undergraduates, and an evolution and science communication workshop at the Aquarium of the Pacific, Long Beach, CA

在有性生殖的生物体中，雄性和雌性在后代中的分配有多种方式，最常见的是通过性染色体（人类和苍蝇中的XX雌性和XY雄性;鸟类和蝴蝶中的ZW雌性和ZZ雄性）。虽然近亲物种的性别决定机制往往不同，但人们对这些物种进化的原因知之甚少。海洋甲壳动物加州虎足虫（Tigriopus californicus）有许多遗传隔离的种群和多基因（遗传的，但非染色体的）性别决定。先前对实验室创造的杂交群体的研究表明，女性而不是男性通常在整个染色体上都是杂合的（每个原始群体都有一个拷贝），这表明它可能是Z/W性染色体。本项目将利用新一代的DNA测序技术，对这个杂交种群及其野生祖先的个体进行鉴定，以确定每个种群的性别决定机制，并确定杂交种群是否进化出了新的性染色体。本项目研究桡足类动物性别决定的遗传基础，桡足类是地球上最丰富的动物群体之一。性染色体是进化的可预测结果。杂交群体中性染色体的出现表明性别决定机制的转换可能是杂交诱导的基因组破坏的结果。这一点特别重要，因为由于人类驱动的过程，如物种引进和气候变化引起的范围转移，自然种群中的杂交越来越多。此外，该项目将包括对本科生的广泛指导，以及在加利福尼亚州长滩太平洋水族馆举办的进化和科学交流研讨会