Molecular Characterization of the Acid-induced Stress Response of Adult Leopard Frog (Rana pipiens)

COLOMBO, M.; RAMESWARAN, M.; WEAVER, F.; BRODKIN, M.; VATNICK, I.*; Widener University, Chester, PA; Widener University, Chester, PA; Widener University, Chester, PA ; Widener University, Chester, PA; Widener University, Chester, PA: Molecular Characterization of the Acid-induced Stress Response of Adult Leopard Frog (Rana pipiens)

Northern leopard frog (Rana pipiens) populations in the Northeast United States are declining. This decline may be caused by the well-documented acidification of aquatic ecosystems in the Northeast and the vulnerability of these frogs to acid-exposure. Last year we presented data demonstrating that acid exposure reduces both the inflammatory response and the phagocytic efficiency of peritoneal exudates cells in adult Rana pipiens. We are currently investigating the effect of acid stress on the molecular mechanisms of innate immunity in these frogs. Our main interest is the acute phase response that is critical in the host pathogen interactions of these frogs. We hypothesized that acid stress suppresses the release of C Reactive Protein (CRP) and therefore the initiation of the innate immune response. We have cloned a partial cDNA for Rana pipiens CRP. Sequence information from this cDNA was used to design primers for real time PCR. Identification of the PCR cycle at which SYBR green fluorescence is detected above background permits comparison of mRNA levels between stressed and unstressed frogs. We obtained preliminary data that is consistent with our hypothesis; lower levels of CRP mRNA were detected in stimulated acid-stressed frogs. Higher levels of CRP mRNA were detected in stimulated frogs held at neutral conditions.

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