Cloning and Phylogenetic Analysis of IFN-r Gene of Gushi Duck

One pair of primers was designed according to duck interferon-gamma(IFN-γ)gene sequences published in GenBank,which was used to amplify the IFN-γ gene from total RNA extracted directly from Gushi duck splenocyte without induction of PHA by reverse transcription-polymerase chain reaction(RT-PCR).The gene fragment was then cloned and sequenced.The result showed that the full length of the amplified duck IFN-γ gene sequence was 515 bp,which includes a open-reading frame(495 bp) and encodes 164 amino acid residues.There are three potential N-glycosalation sites and five cysteines in the deduced amino acid sequence.Compared with the duck IFN-γ gene sequences registered in GenBank,the the nucleotide sequence of Gushi duck IFN-γ gene was the same as AF087134,AF100929 and AJ012254,and shared 99.6% homology with Peking duck IFN-γ gene.Based on the gene sequence comparison and phylogenetic tree analysis,the genus difference was found in IFN-γ gene,and the closer the genetic relationship,the higher the homology.This study paved the way for future study of biological function and application of duck IFN-γ gene.