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United States Department of Agriculture

Agricultural Research Service

Research Project: GENETIC AND GENOMIC APPROACHES TO IMPROVE EFFICIENCY OF SWINE PRODUCTION AND PRODUCT QUALITY

Location: Reproduction Research

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

Authors
item Trenhaile, Melanie -
item Lucot, Katherine -
item Tart, Julie -
item Bundy, Justin -
item Thorson, Jennifer
item Keuter, Elizabeth -
item Wood, Jennifer -
item Rothschild, Max -
item Rohrer, Gary
item Miller, Phillip -
item Spangler, Matthew -
item Lents, Clay
item Johnson, Rodger -
item Kachman, Stephen -
item Ciobanu, Daniel -

Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: January 22, 2014
Publication Date: N/A

Technical Abstract: Age at puberty is a moderately heritable trait and an early indicator of sow reproductive longevity. Gilts that express first estrus early in life 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 uncovered a region on SSC5 (27-28 Mb) that explained the phenotypic variation of both age at puberty and lifetime number of parities. The main candidate in this region is arginine vasopressin receptor 1A (AVPR1A), which is involved in biological processes associated with reproductive and social behavior. 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 3.0 d earlier expression compared with genotype AG (P < 0.08). The GG genotype was also associated with 0.51 more lifetime parities than AA genotype (P < 0.006) and 0.31 more parities than AG genotype (P < 0.06). Irrespective of the expression of first estrus, sows with the GG genotype had a higher probability to generate first and second parities compared to sows with AA and AG genotypes (P <0.05). AVPR1A was expressed in the hypothalamic region, pituitary, granulosa cells, and ovarian cortex. Sequencing AVPR1A in crossbred 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. The NH2-terminus has a role in agonist binding and intracellular signaling. The SNP K377Q is located at the C-terminus known to be 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 the group of gilts that were not able to generate a litter to 0.54 in the 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.

Last Modified: 8/31/2014
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