Technical Abstract: Channel catfish were intraperitoneally challenged with the bacterium Edwardsiella ictaluri and the expression of genes presumed to function in the inducible innate defense was evaluated. End binding protein 1 (EB1), Beta1-integrin, natural resistance associated macrophage protein (Nramp), heat shock protein 70 (Hsp70), serum amyloid P (SAP), and transferrin gene expression profiles were determined using quantitative reverse-transcriptase PCR on liver, anterior kidney (AK), spleen and gut. Fish were sub-sampled at 0, 24, 48, 72, and 96 hours post bacterial or phosphate buffered saline (PBS) injection (hpi). Most transcripts were found universally but SAP and transferrin were liver-specific. In bacterially infected fish, expression of EB1 (AK, spleen and liver), Hsp70 (AK and spleen), Beta1-integrin (liver) and Nramp (spleen and gut) significantly increased by 48 hpi. Transferrin was strongly up-regulated and SAP was down-regulated by 72 hpi, suggestive of positive and negative acute phase reactants. The expression patterns of the catfish genes were similar to that expected during bacteremia. This supports the assumption that the products of the catfish genes have similar defense functions as the mammalian counterparts and that the catfish has a similar innate immune response.