Meeting Abstract

P2-187  Friday, Jan. 6 15:30 – 17:30  Triclosan stimulates the activity of the molting enzyme N-acetyl-beta-glucosaminidase in the epidermis of the fiddler crab, Uca pugilator HAGEN, A.; ZOU, E.*; Nicholls State University; Nicholls State University em.zou@nicholls.edu

Triclosan (TCS), an antimicrobial agent frequently found in aquatic environments, has recently been shown to inhibit crustacean molting. The present investigation sought to understand whether the molt-disrupting effect of TCS arises from disruption of molting hormone signaling. Because of the structural resemblance of TCS to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) capable of disrupting molting hormone signaling, it was hypothesized that TCS would also act through disrupting molting hormone signaling in Crustacea. Exposure of fiddler crabs, Uca pugilator, to TCS at 10 – 250 µg/L for six days had no effect on activity of epidermal N-acetyl-beta-glucosaminidase (NAG), also known as chitobiase, a biomarker for molting hormone signaling. However, TCS at 2500 µg/L significantly increased enzymatic activity, suggesting that TCS at this environmentally unrealistic concentration is capable of enhancing ecdysteroid signaling in vivo. The underlying mechanism for this stimulating effect on epidermal NAG activity needs to be investigated.