Assessing the generality of sexual conflict in new gene evolution in Drosophila

项目摘要 在有性繁殖的物种中，雄性和雌性具有不同的形态、行为和生理特征。 繁殖策略，以达到各自的最佳适应度，同时共享很大程度上相似的基因组。这些 差异可能会导致性冲突，其中一个特定特征的存在可能会导致相反的适应性 对男性和女性的影响。在基因座内性冲突（ISC）中， 可以增加一种性别的适应性，同时减少另一种性别的适应性。 有广泛的证据表明，ISC发生在许多动物，包括人类，和存在 性二态性的存在表明ISC的某些方面是可以解决的。虽然以前的理论和基因 关联研究有助于预测ISC及其缓解策略，但我们仍然缺乏经验性的研究。 哪些基因参与ISC，它们的作用，以及它们对性别特异性适应性的直接影响的证据， 进化 最近，我们的实验室发表了第一个直接证据，表明新基因的进化是通过基因 ISC决议中的重复。我们发现果蝇中一对最近复制的基因 在男性和女性中积累的序列变化和获得的基本的、性别特异性的功能 支持先前的理论预测。这是一个突破性的发现， ISC解决方案可以驱动新的基因进化。然而，这一单一案例研究的一般性仍然存在， 未知 这个提议的目的是定义性冲突驱动的新基因进化的一般性。 我假设，基因座内性冲突的解决可以通过快速的进化来驱动新基因的进化。 获得有助于性别特异性适应的新功能。我将从两个主要方面来检验我的假设 目标。首先，我将使用CRISPR-Cas9辅助的反向遗传方法来评估36个基因的遗传必要性。 新复制的基因通过性别特异性健身测定。到目前为止，我已经敲除了七个新基因， 发现三个基因的功能缺失突变降低了雄性或雌性果蝇的生育能力，这表明它们 可能有助于解决祖先的性冲突。第二，我将进行更深入的 在目标1中检查的五个基因的功能分析，使用组织和单细胞的RNA测序 水平，以确定在解决性冲突中需要新基因功能的途径和细胞类型。我 拟议的研究将基于CRISPR-Cas9的反向遗传学方法与转录组分析相结合， 定义ISC驱动的新基因进化的一般性，以及这些新基因如何促进性别特异性 调解或解决性冲突。

PROJECT SUMMARY In sexually reproducing species males and females have divergent morphologies, behaviors, and reproductive strategies to reach their respective fitness optima while sharing a largely similar genome. These differences can cause sexual conflict, wherein the presence of a particular trait can result in opposite fitness effects in males and females. In intralocus sexual conflict (ISC) the presence of a single gene within a locus can increase the fitness of one sex while decreasing the fitness of the other. There is widespread evidence of ISC occurring in many animals, including humans, and the presence of sexual dimorphism suggests that some aspects of ISC can be resolved. While previous theoretical and gene association studies have helped predict ISC and strategies for its mitigation, we still have little empirical evidence of which genes are involved in ISC, their roles, and their direct impacts on sex-specific fitness in evolution. Recently, our laboratory published the first direct evidence implicating new gene evolution through gene duplication in the resolution of ISC. We found that a pair of recently duplicated genes in Drosophila had quickly accumulated sequence changes and acquired essential, sex-specific functions in male and female reproduction—supporting previous theoretical predictions. This was a groundbreaking finding as it suggests that ISC resolution can drive new gene evolution. However, the generality of this single case study remains unknown. The objective of this proposal is to define the generality of sexual conflict-driven new gene evolution. I hypothesize that intralocus sexual conflict resolution can drive the evolution of new genes through rapid acquisition of novel functions which contribute to sex-specific fitness. I will test my hypothesis in two major Aims. First, I will use a CRISPR-Cas9-aided reverse genetic approach to assess the genetic necessity of 36 newly duplicated genes through sex-specific fitness assays. Thus far I have knocked out seven new genes and found that loss-of-function mutations in three genes reduced the fertility of male or female flies, suggesting they may have contributed to the resolution of an ancestral sexual conflict. Second, I will conduct a deeper functional analysis on five genes examined in Aim 1, using RNA sequencing at both the tissue and single cell levels, to identify pathways and cell types that require new gene functions in resolving sexual conflict. My proposed research combines a CRISPR-Cas9-based reverse genetics approach with transcriptome profiling to define the generality of ISC-driven new gene evolution and how these new genes facilitate sex-specific functions to mediate or resolve sexual conflict.