Fig. 6. The p38 MAPK is present in opercular epithelium and gill epithelial tissue in fully acclimated freshwater and seawater animals. Scans averaged over three immunoblots (top) indicate a lower level of expression of p38 MAPK (bottom) in seawater relative to freshwater levels in both gill and opercular epithelium (^*P<0.05, t-test, N=3).