Vacuolar protein sorting 4 (Vps4) not only functions with its positive regulator vacuolar protein sorting 20‐associated 1 (Vta1) in the multivesicular body (MVB) pathway but also participates alone in MVB‐unrelated cellular processes. However, its physiological roles at the organism level remain rarely explored. We previously identified their respective homologues Bombyx mori Vps4 (BmVps4) and BmVta1 from the silkworm, a model organism for insect research. In this study, we performed fluorescence quantitative real‐time PCR and Western blot to globally characterize the transcription and protein expression profiles of BmVps4 and BmVta1 during silkworm development and in different silkworm tissues and organs. The results showed that they were significantly up‐regulated in metamorphosis, adulthood and embryogenesis relative to larval stages, and displayed a roughly similar tissue‐and‐organ specificity for transcriptions in silkworm larvae. Importantly, BmVps4 was down‐regulated during the early period of the fifth instar, reaching the lowest level of transcription on Day 6, then up‐regulated from Day 7 to the wandering, spinning and pupal stages, and down‐regulated again in adulthood. Moreover, knocking down BmVps4 by RNA interference significantly inhibited silk gland growth, shortened spinning time, prolonged pupation, reduced pupal size and weight, and increased moth wing defects. Together, our data demonstrate the critical and broad requirements for BmVps4 in silkworm metamorphosis.

中文翻译：

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蚕变态需要液泡蛋白分选4。

液泡蛋白分选4（Vps4）不仅与多囊体（MVB）途径中的正调控液泡蛋白分选20相关1（Vta1）一起起作用，而且还单独参与与MVB不相关的细胞过程。然而，其在生物体水平上的生理作用仍然很少被探索。我们先前确定它们各自的同系物家蚕来自家蚕的Vps4（BmVps4）和BmVta1，一种用于昆虫研究的模型生物。在这项研究中，我们进行了荧光定量实时PCR和Western印迹，以全面表征蚕发育过程中以及在不同蚕组织和器官中BmVps4和BmVta1的转录和蛋白质表达谱。结果表明，与幼虫阶段相比，它们在变态，成年和胚胎发生中显着上调，并且对蚕幼虫的转录显示出大致相似的组织器官特异性。重要的是，BmVps4在第五龄初期被下调，在第6天达到最低的转录水平，然后从第7天到徘徊，旋转和p期上调，并在成年后再次下调。此外，通过RNA干扰敲除BmVps4可以显着抑制丝腺生长，缩短纺丝时间，延长化up时间，减少up的大小和重量，并增加蛾翅缺陷。总之，我们的数据证明了BmVps4在家蚕变态中的关键性和广泛性要求。