PARENT SESSION
MA6 - Contaminant Effects on Amphibians & Reptiles
Chair: Bridges, Christine¹, ¹
Co-chair: Krest, Sherry², ²
8:00 AM to 12:00 PM - Monday, 18 November 2002
Room Ballroom B

(216) Molecular and Biochemical Markers of PCB Exposure in California Red-Legged Frogs (Rana aurora draytonii) .

Angermann, Jeff^*,1, Matsumura, Fumio¹, ¹ University of California at Davis, Davis, CA, USA

ABSTRACT- Formerly indigenous to most of California below 5000 feet elevation, the California red-legged frog (CRLF) has disappeared from an estimated 75% of its historical range and is currently listed as Federally threatened and California species of special concern. In June 2001, approximately 39 adult CRLF and 200 tadpoles were removed from a polychlorinated biphenyl (PCB) contaminated site at Vandenberg Air Force Base near Lompoc, CA and transported to UC Davis to investigate sub-lethal effects of PCB bioaccumulation. Half of these frogs were re-exposed to PCBs and the effect of two environmental stressors (cold and dessication) on PCB mobilization, glycogen storage and glucose uptake in liver and muscle was assessed; PCB-induced alterations in protein expression were also determined via novel mRNA induction-based markers of exposure. Among tadpoles raised through metamorphosis and exposed to stressors as subadults, PCB treatment-related changes in glucocorticoid receptor (GR), C/EBP, C/EBP, and cold-inducible RNA-binding protein (CIRP) were evident. The results of this work may contribute to a refinement of regulatory approaches in the management of organochlorine contaminant-exposed amphibians.

Key words: amphibian decline, pcbs, biomarkers, multiple stressors