The porcine gonadotropin-releasing hormone receptor gene (GNRHR): Genomic organization, polymorphisms, and association with the number of corpora lutea

The interaction of gonadotropin-releasing hormone (GNRH) and its receptor ( GNRHR) is critical in the endocrine regulation of reproduction. The gene (G NRHR) encoding the receptor has been mapped to porcine chromosome 8. There is evidence for three quantitative trait loci (QTL) influencing ovulation r ate on this chromosome. We obtained an almost complete sequence (3993 bp, e xcluding intron 1) of the porcine GNRHR gene using PCR-based comparative ge nomic walking and inverse genomic walking approaches. Twelve polymorphisms were detected by sequencing of pooled DNA of Chinese Taihu and European Lar ge White pigs, including 7 base substitutions and 5 insertions-deletions (i ndels). A F-2 population of Meishan X European large White pigs was genotyp ed for a TG indel in the promoter region, and a C/G substitution in the 3' UTR (untranslated region). A significant association of the C/G substitutio n with number of corpora lutea at first parity was observed.