藏猪与雅南猪IGF-I基因的克隆与序列分析

Cloning and sequence analysis of IGF-I gene in Tibetan pig and Yanan pig

为研究IGF-I基因对藏猪、雅南猪生长发育的影响,以Gen Bank中猪IGF-I基因序列(登录号:DQ121132.1)设计引物,提取藏猪、雅南猪肝脏组织总RNA,应用RT-PCR技术克隆出IGF-I基因,分别将藏猪、雅南猪IGF-I基因克隆到PMD19-T载体上,构建重组质粒p MD19-T-IGF-I,经PCR鉴定、测序分析得该基因大小为612 bp,包含一个完整的ORF,该ORF共有462个碱基,编码153个氨基酸;所测得的藏猪和雅南猪基因序列与Muller等报道的猪IGF-I基因编码序列高度同源,序列比对发现,藏猪的同源性为100%,雅南猪的为99.61%;藏猪IGF-I与雅南猪IGF-I基因序列的同源性为99.61%;雅南猪在258 bp处发生A→G突变,但其编码的氨基酸未发生改变。

To study the impact of IGF-I gene on the growth of Tibetan pig and Yanan pig, a pair of primers was de- signed by sus scrofa IGF-I gene sequence from GenBank （Accession number：DQ121132. 1 ）, the total RNAs were ex- tracted by using Trizol from the livers of Tibetan pig and Yanan pig and used as template to amplify IGF-I gene by RT-PCR,the amplified fragments were cloned into pMD19-T vector and the recombinant plasmids pMD19T-IGF-I were constructed and sequenced. The sequencing results indicated that the IGF-I gene consisted of 612 nucleotides, containing a complete ORF of 462 bp ecoding 153 amino acids. The two IGF-I gene sequences shared high homology with the porcine IGF-I gene reported by Muller, et al. , which had an identity of 100% in Tibetan pig and 99. 61% in Yanan pig. It shared 99. 61% homology between the Tibetan pig and Yanan pig IGF-I gene. An A→G mutation oc- curred in the 258 bp of Yanan pig, but the corresponding amino acid was not changed.