Authors : Chang Liu, Zhihui Zhaoa, Wenlin Bai, Boxing Sun, Yonghong Zhang and Runjun Yang
Abstract: Insulin-Like Growth Factor 1 (IGF-1) is a single copy gene. It generates several IGF-1 mRNA variants due to alternative splicing. Spliced variants of IGF-1 being some small peptides derived from spliced variants of IGF-1 have critical roles in cell metabolism and growth of various vertebrate species. Porcine IGF-1 gene has two promoters and the existence of Exon 6 has been confirmed in Songliao Black pig in the laboratory. The aims of the present study were to identify new spliced variants of IGF-1 gene including Exon 5 and to investigate their expression profile in different tissues of Songliao Black pig. The cDNAs of two new spliced variants of IGF-1 gene were cloned by RACE. These two variants were named Class I IGF-1-Eb and Class II IGF-1-Eb, respectively. The Class I IGF-1-Eb contains an Open Reading Frame (ORF) of 564 bp encoding 187 amino acids (GenBank Accession No. FJ914497). The Class II IGF-1-Eb contains an ORF of 516-bp encoding 171 amino acids (GenBank Accession No. FJ914498). Tissue distributions of mRNAs of Class I IGF-1-Eb and Class II IGF-1-Eb were investigated in Songliao Black pig by semi-quantitative RT-PCR. Both of the new mRNA variants were expressed in a variety of tissues. Class I IGF-1-Eb mRNA was more abundant than Class II IGF-1-Eb mRNA in most tissues except for duodenum and longissimus muscle (p<0.05).
Chang Liu, Zhihui Zhaoa, Wenlin Bai, Boxing Sun, Yonghong Zhang and Runjun Yang, 2012. Cloning and Characterization of New Splice Variants of Insulin-Like Growth Factor-1 Gene in Songliao Black Pig. Journal of Animal and Veterinary Advances, 11: 3125-3131.