Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
Dev Cell. 2009 Dec;17(6):885-91. doi: 10.1016/j.devcel.2009.10.008.
Members of the insulin family of peptides have conserved roles in the regulation of growth and metabolism in a wide variety of metazoans. Here we show that Drosophila insulin-like peptide 6 (DILP6), which is structurally similar to vertebrate insulin-like growth factor (IGF), is predominantly expressed in the fat body, a functional equivalent of the vertebrate liver and adipocytes. This expression occurs during the postfeeding stage under the direct regulation of ecdysteroid. We further reveal that dilp6 mutants show growth defects during the postfeeding stage, which results in reduced adult body size through a decrease in cell number. This phenotype is rescued by fat body-specific expression of dilp6. These data indicate that DILP6 is a functional, as well as a structural, counterpart of vertebrate IGFs. Our data provide in vivo evidence for a role of ILPs in determining adult body size through the regulation of postfeeding growth.
胰岛素家族肽在各种后生动物的生长和代谢调节中具有保守作用。在这里，我们表明，与脊椎动物胰岛素样生长因子（IGF）结构相似的果蝇胰岛素样肽 6（DILP6）主要在脂肪体中表达，脂肪体是脊椎动物肝脏和脂肪细胞的功能等效物。这种表达发生在摄食后阶段，受蜕皮激素的直接调节。我们进一步揭示，dilp6 突变体在摄食后阶段表现出生长缺陷，通过减少细胞数量导致成年体大小减小。这种表型可以通过脂肪体特异性表达 dilp6 来挽救。这些数据表明 DILP6 是一种功能性的，以及结构上的，与脊椎动物 IGFs 的对应物。我们的数据提供了体内证据，表明通过调节摄食后生长，ILPs 在决定成年体大小方面发挥作用。
