Submitted to: Molecular Biology Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 8, 2010
Publication Date: April 15, 2011
Repository URL:http://springerlink.com/content/38n0661r37x03mv3/fulltext.pdf Citation: Masopust, M., Vykoukalova, Z., Knoll, A., Bartenschlager, H., Mileham, A., Deeb, N., Rohrer, G.A., Cepica, S. 2011. Porcine insulin receptor substrate 4 (IRS4) gene: cloning, polymorphism and association study. Molecular Biology Reports. 38:2611-2617.
Interpretive Summary: Insulin receptor substrate (IRS) genes are important factors controlling growth and body composition. The gene for IRS4 is expected to map to a region of the pig genome on chromosome X where QTL for backfat have been identified. Therefore, we determined the complete coding sequence of the porcine IRS4 gene. The pig gene product shares 92% identity with human IRS4 and possesses the same important regions as the human protein. We detected single nucleotide polymorphisms (SNP) in the promoter region (96CTechnical Abstract:
Using PCR and IPCR techniques we obtained a 4498 bp nucleotide sequence FN424076 encompassing the complete coding sequence of the porcine IRS4 gene and its proximal promoter. The 1269-amino acid porcine protein deduced from the nucleotide sequence shares 92% identity with the human IRS4 and possesses the same domains and Tyr(P) motifs as the human protein. We detected substitution FN424076:g.96C<G in the promoter region that segregates in Meishan and a synonymous substitution FN424076:g1829T<C in the coding sequence with allele C present only in Meishan. Linkage mapping placed the IRS4 gene at position 82 cM on current USDA –MARC linkage map of porcine chromosome X. Association analyses were performed on 555 animals of 12th –15th generation of the Meishan x Large White cross and showed that both SNPs were highly significantly associated with backfat depth (P = 0.0005) and that the SNP FN424076:g1829T<C was also associated with loin depth (P = 0.017). The Meishan alleles increased backfat dept and decreased loin depth. IRS4 can be considered a positional candidate gene for at least some of QTL located at the centromeric region of porcine chromosome X.