Molecular characterization and expression analysis of two new C-reactive protein genes from common carp (Cyprinus carpio).

C-Reactive protein (CRP) plays an important role in the acute phase response. Transcripts encoding two new CRP-like molecules (ccCRP1 and ccCRP2) from European common carp have been characterized which has enabled seven CRP-like genes to be identified in zebrafish. 79.3% (ccCRP1) and 74.5% (ccCRP2) identity to CRP from East-Asian common carp occurs and fish CRP genes form a distinct clade. ccCRP2 gene organization comprises four exons and three introns, in contrast to the two exons/one intron organization of mammalian CRP genes. Gene expression assays showed both ccCRP-like molecules are constitutively expressed in liver, skin, gill, gut, muscle, kidney, spleen and blood. Protein levels of ccCRP in serum and spleen were significantly different from other organs analyzed, and levels were greatest in the liver. It is proposed that the two carp CRP genes defined differ in their expression profiles which may suggest differences in their biological activities.