Evolution of gamete compatibility and reproductive isolation

配子相容性和生殖隔离的演变

• 批准号: RGPIN-2021-02494
• 负责人: Hart, Michael
• 金额: $ 2.04万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744757
• 关键词: Evolution; gamete; compatibility; reproductive; isolation

Coevolving gene pairs mediate interactions between gametes or between mates, and may be subject to intense sexual selection (sperm competition, reproductive conflicts of interest). This coevolution is of interest to evolutionary biologists because selection on genetic differences among individuals can lead to genetic and reproductive differences between populations and species. The same processes are also of interest to ecologists and physicians because the coevolution of the maternal and paternal genomes can produce coadapted gene pairs with high fertility as well as mismatched pairs with lower fertility. I propose four related studies of reproductive compatibility evolving on different time scales from contemporary within-population differences (in sea stars and humans) to between-species differences (in sister species of sea stars and nudibranchs). We showed that selection on two gamete-binding genes (bindin, OBi1) from two deeply diverging (>70,000 years) populations of the bat star (Patiria miniata) strongly influences sperm-egg compatibility. I now propose to carry out a conceptual replication of that study to test the effects of paternal-maternal mismatches on fertilization rates between mates from the same single population of P. miniata. Such replication studies are rare in evolutionary ecology. We discovered selection and coevolution among three gamete-binding genes (C4BPA, ZP2, ZP3) from human population groups. I now propose to analyze these coevolving pairs of genes in human couples seeking treatment for infertility in western Canada. We ask how maternal-paternal mismatches might account for specific forms of infertility that are amenable to different clinical treatment options. We discovered very recent divergence (<10,000 years) between sister species of sea stars from tropical eastern Australia, including one species with the typical sea star mating system (Cryptasterina pentagona with separate sexes, planktonic fertilization by outcrossing) and one with a highly derived mating system (C. hystera with hermaphrodites, internal self-fertilization, live birth of juveniles). We will take advantage of the impending development of a high-quality Cryptasterina reference genome to assemble and compare multiple genomes from both species, and to find and characterize the genomic regions associated with species differences in sex and reproduction. Our new collaborators in the USA and Canada recently discovered that the charismatic nudibranch Hermissenda crassicornis, which is a model organism in neuroscience, is a complex of three closely related and phenotypically similar species, including H. crassicornis s.s. & H. opalescens from the Pacific coast of North America. Our collaborators shared genomic sequence data for both those species, and we will analyze those data (and collect new data) to discover the demographic history of the speciation event (especially the age of the speciation event, and gene flow between the two species).

共同进化的基因对介导配子之间或配偶之间的相互作用，并可能受到激烈的性选择（精子竞争，生殖利益冲突）。这种共同进化引起了进化生物学家的兴趣，因为对个体间遗传差异的选择会导致种群和物种之间的遗传和生殖差异。同样的过程也引起了生态学家和医生的兴趣，因为母本和父本基因组的共同进化可以产生具有高生育力的共适应基因对以及具有较低生育力的错配基因对。我提出了四个相关的研究生殖相容性从当代种群内的差异（海星和人类）不同的时间尺度上演变到物种间的差异（海星和裸鳃类的姐妹物种）。我们发现，选择两个配子结合基因（bindin，OBi 1）从两个深度分歧（> 70，000年）的蝙蝠星星（Patiria miniata）种群强烈影响精卵相容性。我现在建议进行一个概念性的重复研究，以测试父-母不匹配对同一种群的P. miniata配偶之间受精率的影响。这种复制研究在进化生态学中是罕见的。我们发现了人类群体中三个配子结合基因（C4 BPA，ZP 2，ZP 3）之间的选择和协同进化。我现在建议在加拿大西部寻求不孕症治疗的人类夫妇中分析这些共同进化的基因对。我们问如何母亲-父亲的不匹配可能占特定形式的不孕症，适合不同的临床治疗方案。我们发现了来自热带东澳大利亚的海星姐妹物种之间最近（<10，000年）的分歧，包括一个具有典型海星星星交配系统的物种（Cryptasterina pentagona，具有不同的性别，通过异交进行异源受精）和一个具有高度衍生交配系统的物种（C.雌雄同体，内部自花受精，幼鱼活产）。我们将利用即将开发的高质量的Cryptasterina参考基因组来组装和比较来自两个物种的多个基因组，并找到和表征与性别和生殖方面的物种差异相关的基因组区域。我们在美国和加拿大的新合作者最近发现，有魅力的裸鳃类动物Hermissenda crassicornis是神经科学的模式生物，是三个密切相关且表型相似的物种的复合体，包括H。厚角藻& H.产于北美洲太平洋海岸的乳白色植物。我们的合作者分享了这两个物种的基因组序列数据，我们将分析这些数据（并收集新数据），以发现物种形成事件的人口统计学历史（特别是物种形成事件的年龄，以及两个物种之间的基因流动）。