GWAS identifies two major loci associated with total white marking scores.

<p>A Manhattan plot showing the negative log of the probability of association (p-value) between individual marker and total white marking score. (A) Analysis included horses of all colors, (B) bay horses only, (C) chestnut horses only. Markers are represented in different colors according to their chromosome. Significance level of p≤1×10⁻⁸ is indicated with a dashed red line; a dashed black line represents association with p≤10⁻⁴.