Submitted to: Animal Genetics International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2006
Publication Date: August 20, 2006
Citation: Nonneman, D.J., Wise, T.H., Ford, J.J., Rohrer, G.A. 2006. Characterization of the aldo-keto reductase 1C gene cluster on pig chromosome 10 and association with age of puberty and ovulation rate. (Abstract) Animal Genetics International Conference Proceedings. p. 88. Abstract #D277. Technical Abstract: The rate of pubertal development and weaning to estrus interval are positively correlated and affect reproductive efficiency of swine. Selection for growth rate and leanness in modern commercial pigs has resulted in a delay in the onset of puberty. A QTL for age of puberty has been identified in a Meishan-White composite population on pig chromosome 10q (SSC10) near the telomere, which is homologous to human chromosome 10p15. This region in the human contains an aldo-keto reductase (AKR1C) gene cluster with at least six family members. Aldo-keto reductases (AKR1C) are tissue-specific hydroxysteroid dehydrogenases involved in interconversion of preferred steroid substrates. Screening the porcine CHORI-242 BAC library with a full-length AKR1C4 cDNA identified 7 positive clones and sample sequencing of 5 BAC clones revealed 5 distinct AKR1C genes (AKR1CL2 and AKR1C1-4), which mapped to 126-128 cM on SSC10. TIGR contigs were identified for 4 of the five AKR1C genes; AKR1C1 was not represented in EST libraries. These mRNAs were confirmed by RT-PCR of overlapping fragments or by sequencing individual cDNA clones. Using the IMpRH (7000rad) and IMNpRH2 (12000rad) radiation hybrid panels, these 5 genes mapped between microsatellite markers SWR67 and SW2067 and the gene order was the same as human. Comparison of sequence data with the porcine BAC fingerprint map show that the cluster of genes resides in a 300kb region. SNPs were identified in genomic DNA from parents of the resource population and 10 SNPs were genotyped in 184 gilts observed for age at first estrus and 284 females with ovulation rate from the F8 and F10 generations of one-quarter Meishan descendants of the MARC resource population. Age at puberty and ovulation rate data were analyzed for association by the General Linear Models procedure of SAS with sire and maternal grandsire fitted as fixed effects. One SNP, a phenylalanine to isoleucine substitution in AKR1C2, was associated with age of puberty (p < 0.02) and ovulation rate (p = 0.11) and a SNP in AKR1C4 was associated with ovulation rate (p < 0.01). These 2 SNPs are also segregating in commercial breeds and may be predictive for reproductive performance.