http://equinetapestry.com/2014/04/a-heritable-form-of-brindle-discovered-in-horses/ http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081625#pone-0081625-g002 A friend directed me to the latest update of the Equine Tapestry blog written by Lesli Kathman. The second link is the open access (yay no pay-wall!) paper from PLOS ONE. For you color enthusiasts, as amazing as this discovery is. Do not get too excited until you read up on it. It appears that there is a gene that causes "hair texture" brindle. It is a sex-linked dominant homozygous lethal. It only expresses in females if they have one copy, but it is lethal in males (die in utero) and also lethal in homozygous females. Given the health issues associated with this discovery, it is not a gene that should be bred for in my honest opinion. The lines are caused by stripes of hair having sever skin issues, warts, lesions. They also have eye, hoof, and teeth problems associated with the mutation. On a personal note, I have images of a foal and a few other horses whom I now suspect had this disorder. The images were presented to me by their respective owners, but I do not have permission to post them. One owner posted on another forum asking if allergies could cause a brindle appearance, so now I am suspecting that their mare had this form. The dam of the mare also supposedly had the same "allergies". The fact that they were both female are an important clue to this possibility. This is likely the same sort of mutation that Brenda Batty Atty the famous brindle mare had. However, most of her descendants today do not have this disorder, as it appears to have been bred out of their lines. The curly gene is what the vast majority of her claimed 'brindle' decedents have today. The other horses whom I've seen with what is likely this disorder are from American gaited lines like Brenda Batty Atty herself was suspected of. This disorder could also spontaneously mutate in other breeds. This is starting to put a lot of puzzle pieces together for me personally, so I apologize if I am rambling.