Molecular evolution of the sex peptide network in Drosophila
Molecular evolution of the sex peptide network in Drosophila
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DOI：
10.1111/jeb.13597
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发表时间：
2020-02-10
影响因子：
2.1
通讯作者：
Findlay, Geoffrey D.
中科院分区：
文献类型：
--
作者：
McGeary, Meaghan K.;Findlay, Geoffrey D.
成功的繁殖依赖于许多蛋白质之间的相互作用，而不是那些直接参与配子融合的蛋白质。尽管这些生殖蛋白是随性选择压力而进化的，但随着生殖表型的变化，相互作用的蛋白质网络是如何产生和进化的，仍然是一个悬而未决的问题。在这里，我们研究了果蝇性肽网络的分子进化，这是一个具有良好功能的生殖蛋白网络。在该物种中，性肽荷尔蒙(SP)及其相互作用的蛋白质会在交配后引起雌性生理和行为的重大变化。相比之下，亲缘关系较远的雌性果蝇对SP没有反应。尽管存在这些表型差异，我们还是检测了22个不同果蝇物种的所有网络蛋白的同源基因，并发现有证据表明，大多数同源基因可能在整个属的繁殖中发挥作用。在SP反应物种中，我们检测到了几种网络蛋白的反复适应性进化，这与性别选择的作用是一致的，以不断完善网络功能。我们还发现了一些证据表明，一些蛋白质沿着两个特定的系统发育谱系进行适应性进化，这两个谱系分别对应于雌性生殖道中SP受体表达的增加或精子长度的增加。最后，我们使用基因表达谱来检查通过基因复制产生的SP网络蛋白的平行对偶的功能保守程度。我们的结果提示了SP网络的动态历史，其中网络成员在强健的SP介导的反应开始之前就出现了，然后被净化和正选择所塑造。
Successful reproduction depends on interactions between numerous proteins beyond those involved directly in gamete fusion. Although such reproductive proteins evolve in response to sexual selection pressures, how networks of interacting proteins arise and evolve as reproductive phenotypes change remains an open question. Here, we investigated the molecular evolution of the 'sex peptide network' of Drosophila melanogaster, a functionally well-characterized reproductive protein network. In this species, the peptide hormone sex peptide (SP) and its interacting proteins cause major changes in female physiology and behaviour after mating. In contrast, females of more distantly related Drosophila species do not respond to SP. In spite of these phenotypic differences, we detected orthologs of all network proteins across 22 diverse Drosophila species and found evidence that most orthologs likely function in reproduction throughout the genus. Within SP-responsive species, we detected the recurrent, adaptive evolution of several network proteins, consistent with sexual selection acting to continually refine network function. We also found some evidence for adaptive evolution of several proteins along two specific phylogenetic lineages that correspond with increased expression of the SP receptor in female reproductive tracts or increased sperm length, respectively. Finally, we used gene expression profiling to examine the likely degree of functional conservation of the paralogs of an SP network protein that arose via gene duplication. Our results suggest a dynamic history for the SP network in which network members arose before the onset of robust SP-mediated responses and then were shaped by both purifying and positive selection.