Mutation in bovine [beta]-carotene oxygenase 2 affects milk color

[beta]-Carotene biochemistry is a fundamental process in mammalian biology. Aberrations either through malnutrition or potentially through genetic variation may lead to vitamin A deficiency, which is a substantial public health burden. In addition, understanding the genetic regulation of this process may enable bovine improvement. While many bovine QTL have been reported, few of the causative genes and mutations have been identified. We discovered a QTL for milk [beta]-carotene and subsequently identified a premature stop codon in bovine [beta]-carotene oxygenase 2 (BCO2), which also affects serum [beta]-carotene content. The BCO2 enzyme is thereby identified as a key regulator of [beta]-carotene metabolism. DOI: 10.1534/genetics.109.101741