Insulin signaling pathways in lepidopteran ecdysone secretion

摘要: Molting and metamorphosis are stimulated by the secretion of ecdysteroid hormones from prothoracic glands. Insulin-like have been found to enhance gland activity, providing a mechanism link molting nutritional state. In silk moths (Bombyx mori), glands directly insulin insulin-like hormone bombyxin. Further, in Bombyx , neuropeptide prothoracicotropic (PTTH) appears act at least part through insulin-signaling pathway. Manduca sexta, while stimulates phosphorylation receptor Akt, neither nor bombyxin II stimulate ecdysone secretion. Involvement pathway was explored using two inhibitors phosphatidylinositol-3-kinase (PI3K), LY294002 wortmannin. PI3K block Akt 4EBP but no effect on secretion, or MAPkinase, ERK. Inhibitors that ERK, including MEK inhibitor U0126, high doses RSK SL0101, effectively inhibit The results highlight differences between lepidopteran insects most commonly used study Bombyx, PTTH pathways intersect; both inhibition reduces By contrast, Manduca, action is distinct insulin. species roles translational regulators such as 4EBP, members MAPkinase ERK RSK, effects nutritionally-sensitive molting.