Marine Bio-Tech Fellowship: Variation in a Gamete Recognition Protein of Pacific Sand Dollars

海洋生物技术奖学金：太平洋沙钱鱼配子识别蛋白的变异

• 批准号: 9321243
• 负责人: Michael Hellberg
• 金额: $ 9万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9321243&HistoricalAwards=false
• 关键词: Marine; Bio; Tech; Fellowship; Variation

9321243 Hellberg Closely related species of marine invertebrates commonly occur together and often spawn simultaneously, yet hybrids between these species rarely form. Proteins on the surface of the gametes control species-specific fertilization. Three lines of evidence suggest that changes in these gamete recognition proteins may be involved in the evolution of reproductive isolation: 1) non-fertile heterospecific crosses usually result from the failure of sperm to attach to heterospecific eggs, 2) closely related, reproductively isolated species often show little overall genetic divergence, and 3) selection promotes the divergence of sperm-borne gamete recognition proteins found in different species of abalone. This project will examine two critical questions which remain unanswered: 1) Are interspecific differences in gamete recognition proteins greatest in geographical areas of species overlap, and 2) How variable are gamete recognition proteins within species? These two questions will be addresses by documenting nucleotide sequence variation of the sperm borne gamete recognition protein bindin from both co-occurring and isolated populations of Pacific sand dollars. The project will focus on members of the genus Dendraster, whose geographical distribution (both overlapping and non- overlapping regions) and very recent origins (1 May) should facilitate discrimination between alternative evolutionary mechanisms driving bindin divergence. Finally, the functional significance of both inter-and intraspecific variation in bindin will be examined using pairwise fertilization assays. This research project should produce novel insights into the role of the potential for interspecific hybridization in promoting the divergence of gamete recognition proteins. ***

9321243种与赫尔伯格关系密切的海洋无脊椎动物通常一起出现，并经常同时产卵，但这些物种之间很少形成杂交。配子表面的蛋白质控制物种特定受精。三条证据表明，这些配子识别蛋白的变化可能参与了生殖隔离的进化：1)不育的异种杂交通常是由于精子不能附着到异种卵子上所致；2)密切相关的、繁殖隔离的物种通常表现出很小的总体遗传差异；以及3)选择促进了在不同物种中发现的精子携带的配子识别蛋白的差异。该项目将研究两个尚未解答的关键问题：1)配子识别蛋白在物种地理区域的种间差异是否最大，以及2)配子识别蛋白在物种内的变量有多大？这两个问题将通过记录太平洋沙鱼共生和孤立种群中精子携带的配子识别蛋白结合蛋白的核苷酸序列变异来解决。该项目将侧重于树枝属的成员，其地理分布(重叠和非重叠区域)和最近的起源(5月1日)应有助于区分导致结合差异的其他进化机制。最后，将使用配对受精分析来检验结合素种间和种内变异的功能意义。这项研究项目应该对种间杂交在促进配子识别蛋白分化方面的作用产生新的见解。***