A genomewide association study identified CYP2J2 as a gene controlling serum vitamin D status in beef cattle.

Vitamin D is an important modulator of calcium homeostasis and has several effects on the immune system. The objective of the study was to estimate its heritability and to identify genomic regions associated with concentration of circulating 25-hydroxyvitamin D (25OHD) in beef cattle. Status of vitamin D was measured in crossbred animals from Cycle VII of the United States Meat Animal Research Center (USMARC) Germplasm Evaluation Project. Progeny were born from March through May in 2008 and in 2010. Heritability was estimated and a genomewide association study was conducted on the concentration of 25OHD measured in 1,432 animals at preconditioning and 1,333 animals at weaning. Genotyping of the population was done by imputing from the parental generation genotyped with a high density array (777,000 SNP) to a target population genotyped with a medium density SNP array (50,000 SNP). After imputation, 675,018 SNP were used in the genomewide association study. Heritability of concentration of circulating 25OHD in cattle at preconditioning and at weaning was 0.41 ± 0.08 and 0.32 ± 0.11, respectively. A region on chromosome 3 was associated with circulating 25OHD. The region on BTA3 had 7 SNP significantly (P < 7.4 × 10(-8)) associated at the genomewide level with serum concentrations of serum 25OHD. Genomewide significant SNP spanned the region between 84.93 and 86.65 megabases (Mb); however, 6 SNP reside between 86.64 and 86.65 Mb. The gene CYP2J2 was identified as a candidate gene associated with concentrations of serum 25OHD in cattle. This is 1 of 6 enzymes involved in metabolizing vitamin D to 25OHD. Results from the present study suggest that CYP2J2 is a gene controlling serum 25OHD concentrations in cattle. CYP2J2 should be considered a prime candidate for understanding both genetic and physiological factors affecting serum 25OHD concentrations in cattle and, therefore, vitamin D status.