Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 5/31/2004
Publication Date: 7/25/2004
Citation: Kim, J.G., Vallet, J.L., Christenson, R.K., Rohrer, G.A., Nonneman, D. 2004. Evaluation of an SNP in steroidogenic acute regulatory (STAR) protein for reproductive traits in swine [abstract]. Journal of Animal Science. 82(Supplement 1):65. (Abstract #M258)
Technical Abstract: STAR transports cholesterol from the outer to the inner mitochondrial membrane, which is the rate limiting step for steroidogenesis. STAR mRNA is expressed in reproductive organs including the testis, ovary, and placenta of the pig. The porcine STAR gene was previously mapped by PCR-RFLP analysis to a region that is within one (chromosome 15; 95% confidence interval: 53-101 cM) of several QTL associated with ovulation rate in swine. However, sequence variation in the porcine STAR gene and its association with swine reproductive traits has not been studied. The objectives of this study were to 1) confirm the location of the STAR gene, 2) identify sequence variation in the coding region, and 3) determine the association of STAR gene SNPs with reproductive traits. Primers were designed to amplify and sequence the STAR gene. Two contiguous SNPs (G/C and G/T) in STAR were identified from genomic DNA of Meishan x White composite pigs. The G/T polymorphism changes amino acid 126 from valine to leucine. An assay was designed to genotype the SNP by mass spectrometry. Genotyping of the founders of the resource population indicated that the T allele was found only in Meishans (frequency = 0.81). F2, F8, and F9 gilts with phenotypic data were genotyped for association analysis. Linkage analysis mapped the STAR gene to chromosome 15 position 58.5 cM. Data were analyzed by the General Linear Models procedure of SAS. There was no significant association between the SNP and ovulation rate or age of puberty. Ovulation rate for TT homozygotes (n = 30), GT heterozygotes (n = 90), and GG homozygotes (n = 79) were 12.8 +/ 0.53 (least squares mean +/ standard error), 13.4 +/ 0.32, and 13.4 +/ 0.35, respectively. Age at puberty for TT homozygotes (n = 33), GT heterozygotes (n = 93), and GG homozygotes (n = 97) were 169 +/ 6, 166 +/ 3, and 170 +/ 4 days, respectively. Although STAR is located in a QTL region for ovulation rate in the pig, this polymorphism does not appear to affect ovulation rate or age at puberty significantly.