Genome-wide association studies for resumption of postpartum ovarian cyclicity trait in seasonal anestrus in Spanish Merino sheep breed

To elucidate the genetic basis of reproductive seasonality in Spanish Merino sheep breed, a genome-wide association study (GWAS) in order to detect single nucleotide polymorphisms (SNPs) or regions associated with resumption of ovarian cyclicity during the postpartum period in conjunction with the seasonal anestrus was performed. In total, 169 multiparous Merino ewes which lambed in February were genotyped using the 50k Illumina Ovine Beadchip. After of lambing, blood samples were obtained weekly for measurement of peripheral progesterone concentrations from day 45 to 120. At 72 days of age, lambs were weaned. Live weight, and body condition score of the ewes were also measured. The days from lambing to ovarian activation trait was used for GWAS. An ewe was considered cyclic when the progesterone concentration was higher than or equal to the threshold of 0.5 ng/mL. GCTA software was used for GWAS analysis. Only one SNP (rs161969506) overcame the genome-wide significance level (p_Bonferroni < 0.05) on chromosome 3. Six potential SNPs overcame the chromosome-wise significance level (p_FDR < 0.05). The SNP rs161969506 was located in intron 7 of the KDM3A candidate gene in Oar_Rambouillet 1.0. KDM3A is a demethylase enzyme that has been identified as key regulator of a number of transcription factors, including androgen receptors in the ovary. This gene was partial isolated and Sanger-sequenced, and 5 SNPs were found: 1 SNP in promoter region and 4 nonsynonymous polymorphisms in exons 10 and 17. One and 2 SNPs in promoter and exon 10, respectively, were associated with the studied phenotype in the GWAS population. Haplotype association analysis confirmed the implication of this gene in the studied trait.

Bibliographic Details

Main Authors:	Calvo, Jorge Hugo, Martí, J. I., Lakhssassi, Kenza, García-Méndez, M.S., Sarto, María Pilar, Lahoz, Belén, Bravo-Fernández, J. A., Domingo, A., Serrano Noreña, Magdalena, Alabart, José Luis
Other Authors:	Department of Agriculture (US)
Format:	comunicación de congreso biblioteca
Language:	English
Published:	International Society for Animal Genetics 2023-07-03
Subjects:	GWAS, Merino, Resumption of ovarian activity, Season-ality,
Online Access:	http://hdl.handle.net/10261/352233
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