Meeting Abstract

14.4  Sunday, Jan. 4  Impacts of molt-inhibiting organochlorines on epidermal ecdysteroid signaling in the fiddler crab, Uca pugilator, in vitro MENG, Yanling; ZOU, Enmin*; Nicholls State University, Thibodaux, LA; Nicholls State University, Thibodaux, LA em.zou@nicholls.edu

Organochlorine compounds (OCs) are widely used as industrial and agricultural chemicals. Because of their lipophilicity, these chemicals can readily accumulate in fatty tissues of crustaceans. Several OCs have been reported to have molt-inhibiting effects in Crustacea. To determine whether the molt-inhibition caused by these OCs involves interference with intracellular ecdysteroid signaling in epidermal tissues, the impacts of various molt-inhibiting OCs on N-acetyl-beta-glucosaminidase (NAG) mRNA level in cultured epidermal tissues from the fiddler crab, Uca pugilator, were investigated using quantitative real-time PCR. NAG mRNA was found to be inducible by 20-hydroxyecdysone in cultured epidermal tissues. The results show that, of the six molt-inhibiting OCs tested, methoxychlor is the only one that inhibited the NAG mRNA level, suggesting this OC can suppress epidermal ecdysteroid signaling. Arochlor 1242, PCB29, endosulfan and kepone were found to upregulate the NAG mRNA level in epidermal tissues, suggesting these OCs can stimulate epidermal ecdysteroid signaling, while heptachlor had no effect on NAG mRNA expression in cultured epidermal tissues.