Sun Ya-Ya, Fu Dan-Yang, Liu Bin, Wang Lin-Jun, Chen Hui
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China.
College of Forestry, Northwest A&F University, Xianyang, China.
Front Physiol. 2022 Apr 6;13:865442. doi: 10.3389/fphys.2022.865442. eCollection 2022.
In insects, metamorphosis is controlled by juvenile hormone (JH) and 20-hydroxyecdysone (20E). (), a key JH-early inducible gene, is responsible for the suppression of metamorphosis and the regulation of the () gene, which is induced by 20E and functions as a "pupal specifier". In this study, we identified and characterized the expression patterns and tissue distribution of and at various developmental stages of . The expression of the two genes was induced by JH analog (JHA) methoprene and 20E, and their functions were investigated by RNA interference. and were predominantly expressed in the heads of larvae and were significantly downregulated during the molting stage. In contrast, the transcript level was highest in the adult anterior midgut. was mainly expressed in female adults, with the highest transcript levels in the ovaries. In the larval and pupal stages, both JHA and 20E significantly induced , but only 20E significantly induced , indicating the importance of hormones in metamorphosis. knockdown in larvae upregulated expression, resulting in precocious metamorphosis from larvae to pupae and the formation of miniature pupae. knockdown in pupae suppressed expression, increased emergence, caused abnormal morphology, and caused the formation of small-winged adults. These results suggest that is required for the metamorphosis of . Our findings provide insight into the roles of and in JH-induced transcriptional repression and highlight as a potential target for metamorphosis suppression in .
在昆虫中，变态由保幼激素（JH）和20-羟基蜕皮激素（20E）控制。（）是一个关键的JH早期诱导基因，负责抑制变态并调节（）基因，该基因由20E诱导并作为“蛹特异性因子”发挥作用。在本研究中，我们鉴定并表征了（）在（）不同发育阶段的表达模式和组织分布。这两个基因的表达由JH类似物（JHA）烯虫酯和20E诱导，并通过RNA干扰研究了它们的功能。（）和（）主要在幼虫头部表达，在蜕皮阶段显著下调。相反，（）转录水平在成年前肠中最高。（）主要在成年雌性中表达，在卵巢中转录水平最高。在幼虫和蛹阶段，JHA和20E均显著诱导（），但只有20E显著诱导（），表明激素在变态中的重要性。幼虫中（）基因敲低会上调（）表达，导致幼虫早熟变态为蛹并形成微型蛹。蛹中（）基因敲低会抑制（）表达，增加羽化率，导致形态异常，并导致形成小翅成虫。这些结果表明（）是（）变态所必需的。我们的发现为（）和（）在JH诱导的转录抑制中的作用提供了见解，并突出了（）作为（）中变态抑制的潜在靶点。
