Thanks guys!!! VERY informative!! Lots of stuff that I will certainly use!!
I guess what I kind of meant...is like...when your looking at what I guess you would call a solid, how can you tell what gene is causing the shape of the white pattern (blazes, socks, etc)? Like I read that the sabino will make more symmetrical face markings, which doesn't make sense because theirs normaly have jagged edges when it's on their bodies...
Posted via Mobile Device
Before I begin, there is not a whole lot of information out there that explains exactly what is going on with these genetic modifiers - most of the time the process is unclear.
Looking at a solid bay, black or chestnut it's impossible to tell if it carries any mutation, typically solid paints do not throw color. When you look at a solid "white" horse it is tricky to tell sometimes too, however, the eyes can help clue you in on what is going on (even on a solid agouti/non-agouti) . . .
Even with that said, there a number of diluents that will cause, for instance, blue eyes such as cremello. But every diluent tweaks the animal differently. As previously mentioned, some cause deafness or organ failure.
"The Medicine Hat Paint has been documented as being produced by crossing frame overos on tobianos, sabinos on frame overos and sabinos on tobianos,"(APHA Coat Color Guide, 7). The problem, however, is that multiple copies of Paint genes produce more white on horses and some pairings may create lethal white foals. Additionally, like with ball pythons that mentioned earlier (the pinto python) there is also a blue eyed leucistic python much like a maximom white, blue-eyed paint/pinto horse, that is a "super form" of it's mutation - that is, it is homozygous for such diluent.
My speculation is that "maximum white" sabino horses are homozygous (the more copies of the gene, the more white you get)
Markings can be very hard to define especially because the genes which cause the different patters seem to behave co-dominately. That is, when you mix tobiano + overo you may get a 3rd phenotype (visual representation) - a TOVERO, however, TOBIANO is the only dominant pattern.
My point with all this word garbadge is that you may be trying to label an animal as such but in actuality is actually visually dispalying two or more patterns/genes - this is why it is tricky to TRULLY answer your question.
But for the easy ones I reccomend you take a look at the APHA's color guide: http://www.apha.com/forms/PDFFiles/g...07ColorGen.pdf
It explains what you are looking for as far as pattern differentiation is concerned . . . However, the information is still very superficial as far explaining WHY such things happen.
This website, in my opinion, gives good information on sabino patterns: sabino horses
Hope this helps more . . . If you need help researching further or have a more specific question let me know - I enjoy reading up on this stuff :)