Molecular Cloning and Sequence Analysis of the Gene Encoding Interferon Alpha of the Giant Panda (Ailuropoda melanoleuca)

Abstract

nterferon-alpha (IFN-a) is a kind of cytokines that share antiviral, as well as immunomodulatory, and antiproliferative effects on cell functions. In this report, the cDNA for Ailuropoda melanoleucas interferon alpha was cloned from the ConA-stimulated giant panda peripheral blood mononuclear cells (PBMCs) by RT-PCR. Bioinformatics analysis was performed to predict the characteristics of this gene. Sequencing revealed that the fragment was composed of 495 nucleotides, intronless, encoding a mature polypeptide with 164 amino acids and exhibiting a molecular mass of 18.15 kDa. The analysis of the functional sites and antigenic determinants demonstrated that this protein has 27 functional sites and 9 antigenic determinants, And possesses typical characteristics of interferon alpha, beta and delta family. Compared with 10 corresponding IFN-α sequences. It revealed that the GpIFN-a gene had a close evolutionary relationship with mammalians IFN-a. Phylogenetic tree based on nucleotide sequences showed that giant panda, ferret, dog and cat clustered together and evolved into a distinct phylogenetic lineage. In conclusion, all the data and consequences will provide a basis for further functional study of the Ailuropoda melanoleuca IFN-a.