The Science of Spots

One of the things I love about Ransom, and appaloosas in general, is the fascinating variation in coat patterns. I’m a bit of a nerd when it comes to genetics; that was one of my favorite classes in college. I did my final project on lethal white syndrome in paint horses with overo patterning. These days, I let others do the heavy science for me, and I just read up on their research. My favorite blog on the subject is Lesli Kathman’s The Equine Tapestry.

Ransom displays every classic Appaloosa characteristic: mottled skin, striped hooves, a sparse mane and tail, and the white ring around the eye known as the sclera.  The gene responsible for these, the leopard complex (lp), also modifies his base color (bay) to produce a varnish roan coloring. Ransom is heterozygous for leopard complex (one copy = spots), and the lp gene interacts with a major pattern gene (PATN2) to create his blanket pattern. At least that's the abbreviated version. There are a host of other pattern genes which alter the pattern in subtle ways, all to create one perfect phenotype.