Abstract: The aim of this paper was to amplify full length cDNA genes of Yanbian BoIL-18 and make phylogenetic anylysis.Designing and synthesizing one pair of primers according to bovine IL-18 gene sequences published in GenBank.Bovine IL-18 gene was amplified by RT-PCR from bovine splenic lymphocyte which stimulating by both ConA and PHA for 36 h,then was cloned,double restriction digested and sequenced to identify the positive samples,further to carry out phylogenetic analysis and secondary structure prediction.Having amplified full length cDNA genes of 760 bp of Yanbian BoIL-18,there were two amino acid different.Phylogenetic analysis showed that Yanbian BoIL-18 had high homology with Bos taurus,Capra hircus,Ovis aries,Equus caballus,Sus scrofa,Canis lupus and had low homology with Gallus gallus (51.1%).We make sure the group differences of IL-18 and predicted the secondary structure,laying a foundation for further expressing bovine IL-18, biological activity and utilized as a adjuvant.

Key words: bovine interleukin 18; RT-PCR; phylogenetic analysis