Anyone who has followed the results from the new splashed white tests knows there have been some really surprising results, both in how many horses test negative, and in some of the horses that have tested positive. For those of us that had been studying “classic splash” (splashed white-1) for a while, some of these were perhaps less surprising because we knew that there were blue-eyed horses that looked somewhat like splash, but that did not produce the classic pattern (what we believed to be homozygous). But even there, there have been unexpected surprises. Probably the most dramatic was the Bald Eagle family of Australian Paints. For those that have the Gower color book, this is the splashed white family that was profiled there. I would have guessed (wrongly!) that those were homozygous classic splashes (SW1/SW1) with some type of sabino patterning.
I may have another wrong guess. I have believed that classic splash (SW1) would be found in Marwaris and Kathiawaris. There are certainly horses that have the right kind of pattern. I had hoped that the test on the blue-eyed tovero Marwari above would come up positive, but she was negative. It would have been better if we could have tested one of the horses with the classic pattern like those linked, but it is not a breed with a lot of representatives in the West, so I was tickled to have any blue-eyed horse to sample.
This test coming up negative makes me wonder if those are homozygous splashed white-1 horses, or if there is another mutation that truly makes the same pattern. The Bald Eagle horses at least have some visual differences. I had a particular interest in seeing if the classic pattern (SW1) was in the Marwaris or Kathiawaris because they are so far removed from the breeds where classic splash was first documented. When Valto Klemola found and named the splashed white pattern (what would eventually be splashed white-1) in 1931, he believed it originated in the northern European breeds. It certainly is more prevalent in those breeds than anywhere else except perhaps the American breeds. Finding it in such a genetically distant breeds like the indigenous horses of India would be really interesting, since it would suggest this particular splash mutation is very old.
My friend’s blue-eyed mustang Jag also tested negative for all three splashed patterns and for frame. He has been pictured on the blog before, but here he is again.
It will be interesting to see how many of these horses have splash-type mutations (MITF or PAX3), or if they have unrelated mutations that also happen to give horses blue eyes.