Meeting Abstract

P1.124  Monday, Jan. 4  Cloning and Characterization of Guanylyl Cyclases from the European Green Crab GUNDERSON, J.L.*; MACLEA, K.S.; COVI, J.A.; CHANG, S.A.; CHANG, E.S.; MYKLES, D.L.; Colorado State Univ; Colorado State Univ; Colorado State Univ; UC Davis Bodega Marine Lab; UC Davis Bodega Marine Lab; Colorado State Univ jgundy@ymail.com

The pleiotropic neuropeptide crustacean hyperglycemic hormone (CHH) regulates glucose utilization, molting, osmoregulation, and metabolism in decapod crustaceans. Here we focus on the role of CHH and molt-inhibiting hormone (MIH) in inhibiting ecdysteroidogenesis in the molting gland or Y-organ (YO). CHH signaling is mediated by a membrane receptor guanylyl cyclase (GC-II), while MIH signaling may involve a soluble NO-sensitive guanylyl cyclase (GC-I). RT-PCR and RACE are being used to clone cDNAs encoding GC-I catalytic subunit and GC-II in the green crab (Carcinus maenas). An EST containing a partial GC-II (251 bp: GenBank Accession number DW249653) has been sequenced. Degenerate primers directed against conserved sequences in the GC catalytic domain were used for nested and semi-nested PCR. 3’ and 5’ RACE will be used to obtain the remainder of the sequences. Real-time RT-PCR will be used to quantify the effects of eyestalk ablation (ESA) on GC expression in the YO. ESA removes the primary source of CHH and MIH and activates the YO in most decapods. However, adult C. maenas occur in two color morphs that differ in response to ESA. Red morphs molt infrequently and are resistant to ESA; green morphs molt more frequently and respond to ESA. We hypothesize that GC-I and GC-II are differentially expressed in YOs, which may contribute to the differences between the two morphs in the regulation of molting by eyestalk neuropeptides. Supported by NSF (IOS-0725238).