Spots in olden times

[Pan Zareta]

And the folks doing the research are making the leap that if the LP gene is present, then so are the spots?

You tell me .
This is the first sentence from "Association analysis of candidate SNPs in TRPM1 with leopard complex spotting (LP) and congenital stationary night blindness (CSNB) in horses" (Bellone et al. 2010)-
Leopard complex spotting occurs in several breeds of horses and is caused by a single incompletely dominant autosomal locus, LP.

That statement can be interpreted as no other gene necessary. It's my understanding that the theoretical PATN, which might be multiple genes, is responsible for the distribution of LP markings in the Appaloosa. Don't most of the other breeds in which LP is found exhibit 'allover' or maximal spotting?

It has been interesting to watch (from a safe distance)

[accphotography]

I really don't understand what you're trying to say about The Appaloosa Project's theories Xfactor....????

[summerhorse]

Nobody knows for sure XFactor. We know that LP and PATN are both required for pattern spotting (versus just marble roan). We know that in most of the breeds that carry LP, all or most PATN genes are present because most have all patterns. However we also know that LP and PATN can be bred out of a breed separately. First you have to choose for no patterns, something that PRE and Lusitanos have probably accomplished already (I say probably because there could be a patterned horse lurking somewhere). LP is harder to get rid of because it can be covered by grey and owners would simply hide those horses out back until the grey covered the LP roan! LP can also be expressed very minimally (as American stock horses have found out!) and thus be carried on "under the radar". But it too can be bred out if eyes are sharp!
The Appaloosa breeders in the USA are doing their best it seems to breed both out!

In breeds where LP is just existing (TWH) you can usually trace its very existence to a grey horse covering it.

But you are not going to find the LP gene in a thoroughbred. There is no evidence that it ever existed there. Not surprising considering where the TB was developed.

As far as the prehistoric horses go I believe that the evidence for pattern genes (there are probably at least 3) is the patterns on the horses in paintings. The LP is what they were testing for. Someday they may be able to test for Pattern genes too.

[xfactor fan]

http://www.pedigreequery.com/forum/view ... hp?t=31550

Check out this thread on Courland. That's what I was thinking of with the comment about the LP testing.