Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/17/1999
Publication Date: N/A
Technical Abstract: Recent studies established a significant negative relationship between blood concentration of follicle-stimulating hormone (FSH) and testicular size in mature boars. A genomic scan of over 400 boars for pubertal FSH levels and nearly 200 boars for testicular weight and sperm production identified a possible quantitative trait locus (QTL) on the X chromosome. Based on the location of androgen receptor (AR) and the presence of tri-nucleotide repeat expansions, which are highly variable and related to infertility and testicular dysfunction, in exon 1 of the coding region in humans, we chose AR as a candidate gene for our QTL. Fragments of AR cDNA were generated by RT-PCR from total pituitary RNA of boars with large (N=2, over 300 g) and small (N=2, under 150 g) testes. The expected size of PCR products were sub-cloned and sequenced. The results showed: 1) AR coding sequence consists of 2691 nucleotides, encoding 896 amino acids; 2) the tri-nucleotide repeat (CAG and CGG) expansions in exon 1 are less than observed in humans and are not variable in these boars; 3) the homology of porcine AR to human, mouse and rat is 85, 87, and 87.8% in nucleotide, respectively. The low homology in nucleotide, however, is due to short tri-nucleotide repeats in the exon 1 compared to other species. There is a homology of 90-97% to the other known species in AR nucleotide sequence over exons 2 to 8.