Meeting Abstract
Many currently used pesticides make their way into aquatic environments, and detrimentally affect non-target organisms. Because of its environmental and ecological importance, the blue crab, Callinectes sapidus, was chosen as a model species with which to study primary and secondary disruption of endocrine signaling by pesticides in decapods. Decapods, like all crustaceans, grow discontinuously by molting. Molting is a complex process that requires diverse physiological and structural modifications, including growth of the hypodermis, synthesis of a new exoskeleton, expansion of the body via water uptake, rupturing of the existing skeleton, and hardening of the new exoskeleton. This suite of events is orchestrated by a class of molting hormones termed ecdysteroids. Anthropogenic chemicals that disrupt the production, release or action of ecdysteroids will necessarily impact growth of the organism. In this study, we exposed fresh caught pre-molt (Stage D2) and post-molt (Stage A) blue crabs to physiologically and environmentally relevant concentrations of fenarimol, pyriproxyfen, and tebufenozide. After a 24 h exposure, hemolymph was collected and Y-organs, eyestalk ganglia, epidermis, claw muscle, heart, and hepatopancreas were preserved in RNAlater. The concentration of circulating ecdysteroids was determined by ELISA. Total RNA was isolated and DNase treated prior to reverse transcription. Quantitative PCR will be used to assess the effects of fenarimol, pyriproxyfen, and tebufenozide treatments on the relative abundance of ecdysteroid receptors in tissues from pre- and post-molt crabs.
