合作猪干扰素γ基因的克隆与序列分析

Cloning and Sequence Analysis ofInterferon-γ cDNA of Hezuo Pig

运用RT-PCR和PCR技术克隆基因,应用DNAStar对获得的cDNA及推测的氨基酸序列进行分析。从合作猪脾脏组织中克隆IFN-γcDNA ORF全长501 bp,共编码166个氨基酸,N端具有由23个氨基酸组成的信号肽,该蛋白预测的分子质量为19.418 5 kDa,等电点为9.54,合作猪IFN-γ核苷酸序列上共发现9个磷酸化位点,分别为Ser(7)、Thr(1)、Tyr(1);2个N-糖基化位点,分别在第39位和第106位Asn处。序列比较结果表明,合作猪IFN-γ基因序列与藏猪、印度猪种、内江猪、牛、狗的同源性较高,与人类和鸡的同源性较低。对于小分子蛋白质和多肽,有义突变和无义突变对于同源性及系统进化的分析影响较大,应结合核苷酸和氨基酸2个层面综合分析,并且IFN-γ和高原低氧作用于机体产生的NO,能有效地抑制寄生虫病的发生。

IFN-γ gene was cloned by RT-PCR,the cDNA was cloned and sequenced which structure of its encoding protein were predicted by using DNAStar software.Sequence analysis results showed that the IFN-γ gene ORF was 501 bp and encoded 166 amino acids,including a signal peptide of 23 amino acids（aa） at the N terminal.Relative molecular weight of the encoding protein was 19.418 5 kDa,and the isoelectric point（pI） was 9.54.There were 9 phosphorylation sites including 7 Sers,1 Thr and 1 Tyr.In addition,2 N-glycosylation sites were found at Asn about 39th and 106th in the line.Sense mutation and nonsense mutation in small protein or polypeptide have large influence on the analysis of system evolution and percent identity,so it should be multianalysis on nucleotide and amine acid.IFN-γ and plateau and hypoxia induced body to produce NO.It could inhibit parasitic disease effectively.