A CXC chemokine gene, CXCL12, from rock bream, XXXX : Molecular characterization and transcriptional profile.

@entity1522 @entity462 @entity39745 @entity2348 @entity3689 @entity4149
UNASSIGNED: Chemokines are small, structurally related chemotactic cytokines characterized by the presence of conserved @entity462 residues. In the present study, we identified the cDNA of a CXC chemokine from @entity39745 , designated as OfCXCL12. An open reading frame of 297  bp encoded a 98 @entity3689 peptide with a putative signal peptide of 23 @entity1522 . The CXC family-specific small cytokine domain (SCY), which is highly conserved among vertebrates, was located between residues 29 and 87. The characteristic conserved @entity462 residues in the CXC motif of OfCXCL12 were separated by @entity4149 (Y). Similar to other vertebrate CXCL12 proteins, OfCXCL12 also lacked the ELR motif and hence belongs to ELR(-) subfamily. Phylogenetic analysis revealed two distinct clades, consisting of fish and tetrapod CXCL12 homologs. Constitutive expression with significantly higher levels of OfCXCL12 mRNA transcription was detected in immune-related organs, including the head kidney, spleen, and kidney. Infection with bacterial and viral agents led to significant upregulation of mRNA expression in both the head kidney and spleen, in a stimulant-specific manner. Stimulation of peripheral blood leukocytes by the mitogen concanavalin-A significantly induced OfCXCL12 transcription. Results from the present study suggest an important role for OfCXCL12 in immune defense against @entity2348 in rock bream.
