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This is Reckless Dan, an unusual grey brindle Quarter Horse. Most brindle horses have dark stripes on a lighter body color, but a rare few have white stripes on a dark body color. While it is possible that white brindles are chimeric (and certainly some may be), the current thought is that the color is probably the result of a one-time mutation, probably of rabicano.✨✨
Grey Brindle Quarter Horse: The brindle coat pattern is caused by a rare genetic occurence called chimerism. A chimeric horse develops when fraternal twins fuse into one embryo in utero-- beautiful horse!
How weird!! Love it!! Reckless Dan, a Grey Brindle Quarter Horse. Brindle is what is called a ‘chimeric’ gene. Chimeric genes occur when a mare is pregnant with two non-identical twins, but the two embryos become ‘fused’ into one. What you actually have is two coat colors from two different horses all mixed up. This means chimeric genes, including brindles, are almost totally random and it is almost impossible to breed for it. Geneticists are still trying to figure out the truth behind the brindle gene.