Cloning of two chemokine receptor homologs (CXC-R4 and CC-R7) in rainbow trout Oncorhynchus mykiss

Two rainbow trout chemokine receptors hare been sequenced,,vith homology to CXC-R4 and CC-R7 molecules. The CXC-R4 sequence consisted of 1681 nucleoti des, which translated into a stature protein of 357 amino acids, with 80.7% similarity to human CXC-R4. The CC-R7 sequence consisted of 2287 nucleotid es, which translated into a 368-amino acid mature protein with 64.5% simila rity to human CC-R7, Both sequences contained seven hydrophobic regions, re presenting the seven transmembrane domains (TM) typical of G-protein-couple d receptors, Extracellular cysteines, transmembrane prolines, and the DRY m otif immediately following TM3 were conserved. Phylogenetic tree analysis r evealed a tight clustering of trout CXC-R4 with CXC-R3-5 genes. Trout CC-R7 clustered with CC-R6-7 and. CXC-R1-2. Reverse transcriptase-polymerase cha in reaction analysis demonstrated a wide tissue distribution of CXC-R4 and CC-R7 message in trout, being present in head-kidney leukocytes, blood, gil l, brain, spleen, and liver.