Sequence Characterization of the<i>MC1R</i>Gene in Yak (<i>Poephagus grunniens</i>) Breeds with Different Coat Colors

<jats:p>Melanocortin 1 receptor (<jats:italic>MC1R</jats:italic>) gene plays a key role in determining coat color in several species, including the cattle. However, up to now there is no report regarding the<jats:italic>MC1R</jats:italic>gene and the potential association of its mutations with coat colors in yak (<jats:italic>Poephagus grunniens</jats:italic>). In this study, we sequenced the encoding region of the<jats:italic>MC1R</jats:italic>gene in three yak breeds with completely white (Tianzhu breed) or black coat color (Jiulong and Maiwa breeds). The predicted coding region of the yak<jats:italic>MC1R</jats:italic>gene resulted of 954 bp, the same to that of the wild-type cattle sequence, with >99% identity. None of the mutation events reported in cattle was found. Comparing the yak obtained sequences, five nucleotide substitutions were detected, which defined three haplotypes (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>E</mml:mi><mml:mrow><mml:mi>Y</mml:mi><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math>,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>E</mml:mi><mml:mrow><mml:mi>Y</mml:mi><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math>, and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>E</mml:mi><mml:mrow><mml:mi>Y</mml:mi><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math>). Of the five mutations, two, characterizing the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>E</mml:mi><mml:mrow><mml:mi>Y</mml:mi><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math>haplotype, were nonsynonymous substitutions (c.340C>A and c.871G>A) causing amino acid changes located in the first extracellular loop (p.Q114K) and in the seventh transmembrane region (p.A291T).<jats:italic>In silico</jats:italic>prediction might indicate a functional effect of the latter substitution. However, all three haplotypes were present in the three yak breeds with relatively consistent frequency distribution, despite of their distinguished coat colors, which suggested that there was no across-breed association between haplotypes or genotypes and black/white phenotypes, at least in the investigated breeds. Other genes may be involved in affecting coat color in the analyzed yaks.</jats:p>