Canine coat color genetics is more complicated than the basic 4square charts we did in biology in high school.
I'm not sure if they've figured out the genetics to TEST for when it comes to formentino, but its a function of the dilute genes, as is the blue-brindles.
First off you have to understand that there's two types of Black. Dominant black and recessive black, each controlled by a different gene set.
If a dog is dominant black (K), he may be KK (in which case EVERY pup he he produces will ALSO be black), or Kk (in which case he carries the non-solid black gene).
Recessive black is part of the a gene and I'll get to it in a minute.
Brindle is also a function of K, and is listed as k[SUP]br[/SUP]. A dog who is Kk[SUP]br[/SUP] will appear black but can produce brindle pups. A dog who is k[SUP]br[/SUP]k is brindle but can produce non-brindle pups. And a dog who is k[SUP]br[/SUP]k[SUP]br[/SUP] is brindle and will only produce brindle pups.
Liver is the B gene. B is NOT liver (and will show black hairs unless otherwise modified), and b is liver and will not show black hairs or black leather (liver color). So a dog who's BB will show black hairs and will only produce dogs who show black. A dog who's Bb will show black hairs but can produce dogs who do NOT show black hairs. And a dog who's bb will not show black hairs (or leather) and will only produce pups who do not show black.
Ok, then there's the a gene set. a[SUP]y[/SUP] is "fawn" (may appear anything from red to pale gold controlled by a variety of genes not all of which are understood). a[SUP]w[/SUP] is "wolf sable" sometimes called "wild sable". a[SUP]t[/SUP] produces the black & tan color set. a is recessive black. And they are dominant in the order I listed them. A dog who's a[SUP]y[/SUP]a[SUP]t[/SUP] is "fawn" but can produce black and tan pups. A dog who's a[SUP]y[/SUP]a is "fawn" but can produce recessive black pups.
Those are the basics of canine coat color. From there on out pretty much everything else is cause by modifier genes.
Dilute is D and d. D means the dog is not dilute. d means the dog is. Dilute is what changes black hairs to blue and liver to isabella, or turns a "fawn" dog into cream. A dog who's Dd will show the un-modified black hairs and leather but can produce blue pups (or blue brindle, or formantino). A dog who's bb is dilute and will only produce dilutes.
The G gene has to do with greying. This produces a dog who's born black, with black leather, but who's black hairs turn grey as the dog matures. G is greying, g is not.
Merle produces those funky patterns that get the collies into trouble, its M for merle and m for non-merle.
T is ticking, T[SUP]r[/SUP] is roan, t is neither.
Black masks are E[SUP]m[/SUP], E or e is no black mask. E is sable (sprinkling of black hairs all over the body), e is "clear red" and means the dog shows no black hairs at all but will still have black leather.
And I'm not even going to try to explain white.....not to mention some of the other weird modifies that may be REALLY breed specific!
