Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden.
Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Claude Bernard Lyon, CNRS UMR 5242, Ecole Normale Supérieure de Lyon, 46, allée d'Italie, 69364 Lyon Cedex 07, France.
Proc Biol Sci. 2022 Apr 27;289(1973):20212764. doi: 10.1098/rspb.2021.2764.
Insect wing polyphenism has evolved as an adaptation to changing environments and a growing body of research suggests that the nutrient-sensing insulin receptor signalling pathway is a hot spot for the evolution of polyphenisms, as it provides a direct link between growth and available nutrients in the environment. However, little is known about the potential role of insulin receptor signalling in polyphenisms which are controlled by seasonal variation in photoperiod. Here, we demonstrate that wing length polyphenism in the water strider is determined by photoperiod and nymphal density, but is not directly affected by nutrient availability. Exposure to a long-day photoperiod is highly inducive of the short-winged morph whereas high nymphal densities moderately promote the development of long wings. Using RNA interference we demonstrate that, unlike in several other species where wing polyphenism is controlled by nutrition, there is no detectable role of insulin receptor signalling in wing morph induction. Our results indicate that the multitude of possible cues that trigger wing polyphenism can be mediated through different genetic pathways and that there are multiple genetic origins to wing polyphenism in insects.
昆虫翅膀多态性的进化是对环境变化的一种适应，越来越多的研究表明，营养感应胰岛素受体信号通路是多态性进化的热点，因为它为生长和环境中可用营养物质之间提供了直接联系。然而，对于由光周期季节性变化控制的多态性，胰岛素受体信号的潜在作用知之甚少。在这里，我们证明了水黾的翅膀长度多态性是由光周期和若虫密度决定的，但不受营养供应的直接影响。暴露在长日照下高度诱导短翅型，而高密度的若虫则适度促进长翅的发育。使用 RNA 干扰，我们证明与在其他几种由营养控制翅膀多态性的物种不同，胰岛素受体信号在翅膀形态诱导中没有可检测到的作用。我们的结果表明，触发翅膀多态性的多种可能线索可以通过不同的遗传途径来介导，并且昆虫的翅膀多态性有多个遗传起源。
