Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan.
National Agriculture and Food Research Organization, 305-8634 Tsukuba, Japan.
Proc Natl Acad Sci U S A. 2021 Jan 5;118(1). doi: 10.1073/pnas.2020028118. Epub 2020 Dec 21.
Diapause represents a major developmental switch in insects and is a seasonal adaptation that evolved as a specific subtype of dormancy in most insect species to ensure survival under unfavorable environmental conditions and synchronize populations. However, the hierarchical relationship of the molecular mechanisms involved in the perception of environmental signals to integration in morphological, physiological, behavioral, and reproductive responses remains unclear. In the bivoltine strain of the silkworm , embryonic diapause is induced transgenerationally as a maternal effect. Progeny diapause is determined by the environmental temperature during embryonic development of the mother. Here, we show that the hierarchical pathway consists of a γ-aminobutyric acid (GABA)ergic and corazonin signaling system modulating progeny diapause induction via diapause hormone release, which may be finely tuned by the temperature-dependent expression of plasma membrane GABA transporter. Furthermore, this signaling pathway possesses similar features to the gonadotropin-releasing hormone (GnRH) signaling system for seasonal reproductive plasticity in vertebrates.
滞育代表昆虫发育的重大转变，是一种季节性适应，作为大多数昆虫物种休眠的特定亚型进化而来，以确保在不利环境条件下的生存，并使种群同步。然而，参与环境信号感知的分子机制的层次关系到形态、生理、行为和生殖反应的整合仍不清楚。在桑蚕的两化性品系中，胚胎滞育作为母体效应被跨代诱导。后代滞育由母亲胚胎发育过程中的环境温度决定。在这里，我们表明，这个层次途径包括一个γ-氨基丁酸（GABA）能和心激素信号系统通过释放滞育激素来调节后代滞育的诱导，这可能通过质膜 GABA 转运体的温度依赖性表达进行精细调节。此外，这个信号通路具有与脊椎动物促性腺激素释放激素（GnRH）信号系统相似的特征，用于季节性生殖可塑性。
