Immune-relevant (including acute phase) genes identified in the livers of rainbow trout, Oncorhynchus mykiss, by means of suppression subtractive hybridization

To develop tools for analysis of the acute phase response, we used suppress ion subtractive hybridization of cDNAs from the livers of trout in an uncha llenged state and in the course of a response to injection with a Vibrio ba cterin emulsified in Freund's Incomplete Adjuvant. The resulting cDNA libra ry contains 300-600 bp long fragments of 25 or more immune-relevant genes. Fifteen were previously unreported for salmonids, and 12 were not known fro m any fish species. Known acute phase proteins include serum amyloid A, tra nsferrin and precerebellin-like protein; trout C-polysaccharide-binding pro tein I is probably also an acute phase protein. Components of both the comp lement system (n = 5) and the clotting system (n = 3), as well as lectins, various binding proteins, a putative antibacterial peptide, a chemotaxin, a n anti-oxidant enzyme, as well as some likely cell-surface receptors and me tabolic and lysosomal enzymes are represented in the library. One clone clo sely resembles a group of Toll-like receptors, including the human LL-I rec eptor. Three cDNAs appear to represent complete open reading frames. (C) 20 01 Elsevier Science Ltd. All rights reserved.