Meeting Abstract

P2.32B  Monday, Jan. 5  Comparative analysis of NOS signaling in the crustacean molting gland MCDONALD, A.A*; ATCHISON, L.A.; CHANG, E.S.; COVI, J.A.; MYKLES, D.L.; Colorado State University, Fort Collins; Colorado State University, Fort Collins; UC Davis Bodega Marine Lab, Bodega Bay; Colorado State University, Fort Collins; Colorado State University, Fort Collins aud.mcdonald@gmail.com

Molting in crustaceans is regulated by ecdysteroids produced in the Y-organs (YO) located in the lateral cephalothorax. Ecdysteroid secretion by the YO is suppressed in the presence of molt-inhibiting hormone (MIH), a neuropeptide produced in the X-organ of the eyestalk ganglia (EG). The binding of MIH to its cell surface receptor in the YO activates a signal transduction cascade, resulting in decreased production of ecdysteroids. Recent research indicates that the pathway may involve nitric oxide synthase (NOS), an enzyme which catalyzes the production of nitric oxide from oxygen and arginine and is known to be expressed in the YO. Additional research shows that the sensitivity of the YO to MIH varies over the molting cycle. Increases in expression of signaling proteins such as NOS could increase sensitivity of the MIH pathway. To illuminate the role of NOS, we eyestalk ablated (ESA) two species of decapod crustaceans, the land crab Gecarcinus lateralis and green crab, Carcinus maenas. Eyestalk ablation removes the endogenous source of MIH and activates the YO. Expression of NOS is quantified with real-time PCR. Preliminary results indicate that ESA increases expression of NOS mRNA in the land crab. Supported by National Science Foundation. (IBN-0342982 and IOS-0745224)