State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory of Sericultural Science, Southwest University, Chongqing 400715, China.
Medical Research Institute, Wuhan University, Wuhan 430071, China; Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
Cell Rep. 2022 Feb 22;38(8):110397. doi: 10.1016/j.celrep.2022.110397.
Insect salivary glands have been previously shown to function in pupal attachment and food lubrication by secreting factors into the lumen via an exocrine way. Here, we find in Drosophila that a salivary gland-derived secreted factor (Sgsf) peptide regulates systemic growth via an endocrine way. Sgsf is specifically expressed in salivary glands and secreted into the hemolymph. Sgsf knockout or salivary gland-specific Sgsf knockdown decrease the size of both the body and organs, phenocopying the effects of genetic ablation of salivary glands, while salivary gland-specific Sgsf overexpression increases their size. Sgsf promotes systemic growth by modulating the secretion of the insulin-like peptide Dilp2 from the brain insulin-producing cells (IPCs) and affecting mechanistic target of rapamycin (mTOR) signaling in the fat body. Altogether, our study demonstrates that Sgsf mediates the roles of salivary glands in Drosophila systemic growth, establishing an endocrine function of salivary glands.
昆虫的唾液腺先前被证明通过外分泌的方式将分泌物分泌到腔中，从而在蛹的附着和食物润滑中发挥作用。在这里，我们在果蝇中发现，一种唾液腺衍生的分泌因子（Sgsf）肽通过内分泌的方式调节全身生长。Sgsf 特异性表达于唾液腺并分泌到血淋巴中。Sgsf 敲除或唾液腺特异性 Sgsf 敲低均会减小身体和器官的大小，表型类似于唾液腺遗传消融的效果，而唾液腺特异性 Sgsf 过表达则会增加它们的大小。Sgsf 通过调节来自脑胰岛素产生细胞（IPCs）的胰岛素样肽 Dilp2 的分泌以及影响脂肪体中的雷帕霉素靶蛋白（mTOR）信号来促进全身生长。总的来说，我们的研究表明 Sgsf 介导了唾液腺在果蝇全身生长中的作用，确立了唾液腺的内分泌功能。
