DEB: Genomics of Sexual Selection in Pipefishes and Seahorses

性选择是一种重要的进化机制，它导致了奢侈的装饰、强烈的交配偏好和两性之间的差异。性选择也为性冲突埋下了温床，在这种情况下，两性的进化利益不一致，导致某些特征或基因对一方有利，但对另一方有害。虽然性选择和性冲突对性状的影响已被很好地理解，但对这些机制如何影响基因组却知之甚少。对性选择、性冲突和基因组进化相关理论的一个关键测试，将需要对相关物种群体进行基因组比较，其中一些物种有强性选择的历史，而另一些物种有弱性选择的历史。在这个项目中，研究人员将使用海马和相关的管鱼来进行这样的测试。海马和一些管鱼是一夫一妻制的，有长期的伴侣关系，这种交配制度导致了较弱的性选择和很少的性冲突。其他管鱼独立地进化出了一夫多妻制（一种或两种性别的多次交配），这导致了强烈的性选择和大量的冲突。研究人员将运用现代测序方法来描述性选择和冲突对这些物种基因组进化的影响。这个项目的意义远远超出了海马和管鱼，因为包括人类在内的许多物种在最近的进化史上都涉及到性选择和冲突。这段历史可以解释为什么两性在基因组水平上是不同的，以及为什么相同的基因对两性有不同的影响。该项目还将在尖端基因组技术和统计方法方面培养新一代的研究生和本科生。此外，它还将通过提供为期一周的研讨会和公开基因组数据的新财富，扩大管鱼和海马的研究社区。该项目将涉及12个分类群，包括3个海马和9个管鱼，根据它们的系统发育关系和已知的性选择模式进行选择。海马属（Hippocampus）和三种管鱼属（Doryrhampus）是一夫一妻制的，有配偶关系，而其他六种管鱼（Syngnathus属和Nerophis属各有三种）是一夫多妻制的，具有强烈的性选择历史。该项目将包括：(1)对所有12个分类群的基因组进行完整测序，(2)比较转录组学，这将检查性别特异性基因表达的模式，以及(3)比较种群基因组学，这将检测当代基因组水平的选择。数据将被整合到这三个层次的方法中，以理解进化理论中性选择和性冲突在基因组水平上的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Sexual selection is an important evolutionary mechanism that results in the evolution of extravagant ornaments, strong mating preferences, and differences between the sexes. Sexual selection also sets the stage for sexual conflict, a situation in which the evolutionary interests of the two sexes fail to coincide, resulting in traits or genes that can be beneficial to one sex but harmful to the other sex. While the effects of sexual selection and conflict on traits are well understood, little is known about how these mechanisms affect the genome. A key test of theory relating sexual selection, sexual conflict and genome evolution would entail genome comparisons in groups of related species in which some have had a history of strong sexual selection and some have had a history of weak sexual selection. In this project, the researchers will use seahorses and the related pipefishes to conduct such a test. Seahorses and some pipefishes are monogamous with long-term pair-bonds, and this mating system results in weak sexual selection and little sexual conflict. Other pipefishes have independently evolved polygamy (multiple mating by one or both sexes), which results in strong sexual selection and substantial conflict. The researchers will apply modern sequencing methodologies to delineate the impacts of sexual selection and conflict on genome evolution in these species. This project has significance well beyond seahorses and pipefishes, as many species, including humans, have had a recent evolutionary history involving sexual selection and conflict. This history can explain why the sexes are different at the level of the genome and why the same gene can have different effects in the sexes. This project will also train a new generation of graduate students and undergraduates in cutting-edge genomic techniques and statistical methodologies. In addition, it will expand the pipefish and seahorse research community by offering week-long workshops and a new wealth of publicly available genomic data.The project will involve a total of twelve taxa, including three seahorses and nine pipefishes, chosen for their phylogenetic relationships and known patterns of sexual selection. The seahorses (genus Hippocampus) and three of the pipefish species (genus Doryrhampus) are monogamous with pair-bonds, and the other six pipefish (three each from the genera Syngnathus and Nerophis) are polygamous with a history of strong sexual selection. The project will involve (1) the complete sequencing of the genomes of all twelve taxa, (2) comparative transcriptomics, which will examine patterns of sex-specific gene expression, and (3) comparative population genomics, which will detect contemporary genome-level selection. Data will be integrated across these three levels of approaches to understand the genome-level effects of sexual selection and sexual conflict in light of evolutionary theory.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.