DNA cloning and characterization of an allograft inflammatory factor-1 homologue in red sea bream ( Chrysophrys major)

Abstract

We isolated allograft inflammatory factor-1 (AIF-1) homologue cDNA from lipopolysaccharide (LPS)-stimulated red sea bream leukocytes. We then determined that this cDNA encodes 444 bp in length and has an open reading frame that encodes 142 amino acids. The deduced amino acid sequence was homologous to the AIF-1s in carp and mammals (>65.5% sequence identity). The nucleotide sequence of the protein-coding region in the AIF-1 gene was determined to have six exons and five introns. The exon–intron structure resembles those of the mouse and the human. Genomic Southern blot analysis revealed the presence of a single AIF-1 gene per haploid in red sea bream. A time course evaluation indicated that the expression level of AIF-1 gene in LPS-stimulated leukocytes was static in the first hour, but gradually increased from 3 to 24 h. The similarities between AIF-1s in mammals and red sea bream suggest that the AIF-1 in red sea bream may have a similar function in activated leukocytes as AIF-1s do in mammals.