Ecdysteroid titer determines the state of the cell cycle in silkworm (Bombyxmori) metamorphosis. However, the mechanism of this process is unclear. In this study, we demonstrated that the BmFoxO gene participates in the regulation of the cell cycle induced by 20-Hydroxyecdysone (20E) in BmN-SWU1 cells. The 20E blocks the cell cycle in the G2/M phase through the ecdysone receptor (EcR) and inhibits DNA replication. The 20E can promote BmFoxO gene expression. Immunofluorescence and Western blot results indicated that 20E can induce BmFoxO nuclear translocation in BmN-SWU1 cells. Overexpression of the BmFoxO gene affects cell cycle progression, which results in cell cycle arrest in the G0/G1 phase as well as inhibition of DNA replication. Knockdown of the BmFoxO gene led to cell accumulation at the G2/M phase. The effect of 20E was attenuated after BmFoxO gene knockdown. These findings increase our understanding of the function of 20E in the regulation of the cell cycle in B. mori.

中文翻译：

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BmFoxO基因调控的20羟蜕皮激素在BmN-SWU1细胞中的细胞周期

蜕皮甾体滴度确定在蚕细胞周期（状态家蚕家蚕）变态。但是，此过程的机制尚不清楚。在这项研究中，我们证明了BmFoxO基因参与BmN-SWU1细胞中20-羟基蜕皮激素（20E）诱导的细胞周期的调控。20E通过蜕皮激素受体（EcR）阻止G2 / M期的细胞周期，并抑制DNA复制。20E可以促进BmFoxO基因表达。免疫荧光和蛋白质印迹结果表明20E可以诱导BmN-SWU1细胞中BmFoxO核易位。BmFoxO的过表达该基因影响细胞周期进程，导致细胞周期停滞在G0 / G1期并抑制DNA复制。击倒BmFoxO基因导致细胞在G2 / M期积累。BmFoxO基因敲低后减弱了20E的作用。这些发现增加了我们对20E在B. mori细胞周期调控中的功能的了解。