Control of the ecdysteroid level plays a crucial role in density-dependent metamorphosis in the giant mealworm beetle Zophobas atratus
Control of the ecdysteroid level plays a crucial role in density-dependent metamorphosis in the giant mealworm beetle Zophobas atratus
复制标题
蜕皮类固醇水平的控制在巨型黄粉虫 Zophobas atratus 的密度依赖性变态中起着至关重要的作用
DOI：
10.1016/j.ydbio.2021.01.014
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发表时间：
2021
影响因子：
2.7
通讯作者：
Togawa Toru
中科院分区：
文献类型：
--
作者：
Toga Kouhei;Homma Yuri;Togawa Toru
一些拟步甲的变质转变取决于种群密度。这种现象对容易吃同类的人很有用。这种适应性发育现象的生理机制尚不清楚。黑足鼠的变态是密度依赖性的，幼虫隔离可以诱导其变态。我们在此表明，返回孤立的幼虫到拥挤的条件（重新拥挤）抑制他们的变态。根据隔离幼虫经历的重新拥挤的持续时间，变质开始的时间略有延长。因此，重新拥挤诱导的生理变化需要变态抑制。我们研究了参与变态抑制剂（保幼激素，JH）和蜕皮激素（蜕皮激素）信号转导的蜕皮相关基因是否对重新拥挤做出反应。表达分析表明，蜕皮激素信号转导的基因表达在再拥挤条件下维持在低水平。事实上，蜕皮激素水平下降响应重新拥挤。蜕皮激素注射诱导变态在重新拥挤的幼虫。与此相反，JH信号基因表现出很小的波动，在隔离和重新拥挤的条件下，和JH信号因子的敲除不影响变态的抑制下重新拥挤的条件。本研究表明，蜕皮激素水平的调节，而不是JH是更重要的密度依赖变态在Z.atratus。
Metamorphic transition in some tenebrionid beetles is dependent on population density. This phenomenon is useful for pupae that are vulnerable to cannibalism. The physiological mechanism of this adaptive developmental phenomenon remains unclear. InZophobas atratus, which show density-dependent metamorphosis, larval isolation can induce metamorphosis. We herein demonstrated that the return of isolated larvae to a crowded condition (re-crowding) inhibited their metamorphosis. The timing of metamorphic initiation was slightly extended according to the duration of re-crowding experienced by the isolated larvae. Therefore, the re-crowding induced physiological changes needed for metamorphic inhibition. We investigated whether hormone-related genes involved in signaling of metamorphic inhibitor (juvenile hormone, JH) and molting hormone (ecdysteroid) responded to the re-crowding. An expression analysis showed that gene expression of ecdysteroid signaling was maintained at low levels under the re-crowded condition. Actually, ecdysteroid levels decreased responding to re-crowding. Ecdysteroid injections induced metamorphosis in re-crowded larvae. In contrast, the JH signaling gene showed little fluctuation in both isolated and re-crowded conditions, and knockdown of JH signaling factors did not affect inhibition of metamorphosis under the re-crowded condition. The present study suggests that regulation of ecdysteroid level rather than JH is more crucial in the density dependent metamorphosis inZ.atratus.