Convergent and complementary selection shaped gains and losses of eusociality in sweat bees
Convergent and complementary selection shaped gains and losses of eusociality in sweat bees
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DOI：
10.1038/s41559-023-02001-3
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发表时间：
2023-03-20
影响因子：
16.8
通讯作者：
Kocher，Sarah D.
中科院分区：
文献类型：
--
作者：
Jones，Beryl M.;Rubin，Benjamin;Kocher，Sarah D.
汗蜂不断地获得和失去群居性，从个体繁殖到群体繁殖的过渡。在这里，我们生成了17个物种的染色体长度基因组集合，并确定了与社会生活和独居生活过渡相关的进化权衡的基因组特征。年轻基因和调控区域都显示出这些分子模式的富集。我们还发现了一些位点，这些位点显示出积极选择和放松选择的互补信号，这些信号与汗蜂社会性的趋同收益和损失特别相关。这包括两种多效性蛋白质，它们结合和运输幼体激素（JH）——昆虫发育和繁殖的关键调节因子。我们发现其中一种蛋白质主要在形成昆虫血脑屏障的神经胶质细胞下表达，并且大脑中JH的水平因社会性而异。我们的发现与JH在调节社会行为中的作用是一致的，并表明结合和运输JH的蛋白质的改变促进了社会进化，揭示了一种祖先的发育激素是如何在生命的一个主要转变中被选择的。更广泛地说，我们的研究结果强调了进化权衡如何构建了这些蜜蜂群居性的分子基础，并展示了方向选择和摆脱约束如何影响特征进化。
Sweat bees have repeatedly gained and lost eusociality, a transition from individual to group reproduction. Here we generate chromosome-length genome assemblies for 17 species and identify genomic signatures of evolutionary trade-offs associated with transitions between social and solitary living. Both young genes and regulatory regions show enrichment for these molecular patterns. We also identify loci that show evidence of complementary signals of positive and relaxed selection linked specifically to the convergent gains and losses of eusociality in sweat bees. This includes two pleiotropic proteins that bind and transport juvenile hormone (JH)—a key regulator of insect development and reproduction. We find that one of these proteins is primarily expressed in subperineurial glial cells that form the insect blood–brain barrier and that brain levels of JH vary by sociality. Our findings are consistent with a role of JH in modulating social behaviour and suggest that eusocial evolution was facilitated by alteration of the proteins that bind and transport JH, revealing how an ancestral developmental hormone may have been co-opted during one of life’s major transitions. More broadly, our results highlight how evolutionary trade-offs have structured the molecular basis of eusociality in these bees and demonstrate how both directional selection and release from constraint can shape trait evolution.