Meeting Abstract

P1.122  Monday, Jan. 4  Studies on the signaling pathways regulating facultative and constitutive ecdysteroidogenesis in the crustacean molting gland REGELSON, K.W.*; COVI, J.S.; CHANG, S.A.; CHANG, E.S.; MYKLES, D.L.; Colorado State Univ; Colorado State Univ; UC Davis Bodega Marine Lab; UC Davis Bodega Marine Lab; Colorado State Univ aindeamhan@gmail.com

Ecdysteroidogenesis in the molting gland, or Y-organ (YO), of decapod crustaceans is controlled by neuropeptides, molt-inhibiting hormone (MIH) and crustacean hyperglycermic hormone, produced in the X-organ/sinus gland in the eyestalks. Cyclic nucleotides mediate MIH control of YO ecdysteroidogenesis: cGMP primarily inhibits facultative synthesis, while cAMP primarily inhibits constitutive synthesis. MIH inhibition of facultative ecdysteroidogenesis may involve activation of NO-sensitive guanylyl cyclase, as NO donors can inhibit ecdysteroid synthesis. As constitutive synthesis requires translation of mRNA to protein, we hypothesized that cAMP suppresses insulin/metazoan Target of Rapamycin (mTOR) signaling. We are using in vitro YO culture to determine the effects of recombinant MIH and signaling antagonists on YO ecdysteroidogenesis. Eyestalk ablation (ESA) was used to activate YOs from blackback land crab, Gecarcinus lateralis, and green crab, Carcinus Maenas. Using reagents to block the activities of signaling molecules, we can identify components of the MIH signaling pathway. In addition, rapamycin will be used to examine the role of the mTOR pathway in the constitutive production of ecdysteroids. Supported by NSF (IOS-0725238).