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AVPR1A alleles are pleiotropic sources of variation in age at puberty and reproductive longevity in sows

Wednesday, March 19, 2014: 9:45 AM
306-307 (Community Choice Credit Union Convention Center)
Melanie D. Trenhaile , University of Nebraska - Lincoln, Lincoln, NE
Katherine L. Lucot , University of Nebraska, Lincoln, NE
Julie K. Tart , University of Nebraska, Lincoln, NE
Justin W. Bundy , University of Nebraska, Lincoln, NE
Jennifer F. Thorson , USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE
Elizabeth M. Keuter , University of Nebraska, Lincoln, NE
Jennifer R. Wood , University of Nebraska, Lincoln, NE
Max F. Rothschild , Iowa State University, Ames, IA
Gary A. Rohrer , USDA/ARS, Clay Center, NE
Phillip S. Miller , University of Nebraska, Lincoln, NE
Matthew L. Spangler , University of Nebraska, Lincoln, NE
Clay A. Lents , USDA, ARS, U.S. Meat Animal Research Center, Clay Center, NE
Rodger K. Johnson , University of Nebraska - Lincoln, Lincoln, NE
Stephen D. Kachman , University of Nebraska - Lincoln, Lincoln, NE
Daniel C. Ciobanu , University of Nebraska, Lincoln, NE
Abstract Text:

Age at puberty is a moderately heritable trait and an early indicator of sow reproductive longevity. Gilts that express first estrus early are characterized by improved reproductive longevity and lifetime productivity. These traits are dependent on the function of the hypothalamic-pituitary-gonadal axis, and their variation is expected to be affected by the same genes. Genome-wide association analyses uncovered a region on SSC5 (27-28 Mb) that partially explained the phenotypic variation of age at puberty and lifetime number of parities. The main candidate gene in this region, arginine vasopressin receptor 1A (AVPR1A), involved in biological processes associated with reproductive and social behavior, was characterized to assess its efficiency as a selection marker for early age at puberty and increased reproductive longevity. The GG genotype of a non-synonymous SNP located in AVPR1A (G31E) was associated with a 4.6 d earlier expression of first estrus compared with genotype AA (P < 0.05) and a 3.0 d earlier expression than genotype AG (P < 0.08). The GG genotype was also associated with 0.51 more lifetime parities than AA (P < 0.006) and 0.31 more than AG (P < 0.06). Irrespective of age at puberty, sows with the GG genotype had a higher probability of generating first and second parities than sows with AA and AG genotypes (P < 0.05). AVPR1A is expressed in the pituitary, granulosa cells, and ovarian cortex. Sequencing AVPR1A in gilts exhibiting puberty early (134-149 d, n=8) and late (219-243 d, n=8) uncovered two novel non-synonymous SNPs (G256D and K377Q). SNP G256D is located in the third intracellular loop of AVPR1A and was in complete linkage disequilibrium with G31E, located in the extracellular NH2-terminus, which has a role in agonist binding and intracellular signaling. The SNP K377Q is located at the C-terminus, involved in coordinating protein interactions with AVPR1A. A 0.19 difference in allelic frequency was observed between gilts that expressed puberty early and late for G31E and G256D compared to 0.06 for K377Q. The frequency of the favorable allele A from G31E increased from 0.42 in gilts unable to generate a parity to 0.54 in sows that generated 3 parities. These differences suggest that selection based on SNPs such as G31E and G256D have the potential to reduce age at puberty and improve reproductive longevity, leading to an increase in sow net values in commercial herds. USDA is an equal opportunity provider and employer.

Keywords: swine, AVPR1A, longevity

See more of: Breeding and Genetics II
See more of: Breeding and Genetics
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