Originally Posted by peppersb
Zyrcona -- The amount of information about genetics that you have shared here is just amazing. Thank you so much! I can't wait to see your book.
Thanks. Here’s what I’m currently using for a working theory. As usual, it’s subject to change should some more information come to light. I don’t think I have enough data on some of these genes to write a book on it yet.
I’ve found most of my observations agree best with Dr John Armstrong’s theories Color Genes in the Poodle
and most of my own thoughts on the unidentified genes are based on his. Apologies for the superscripts and subscripts not coming through.
(these are all mapped genes that have been scientifically demonstrated to exist and ascribed to these particular colour traits):
E eumelanin (black or brown coat)
e phaeomelanin (red, apricot, cream, or white coat)
B black eumelanin
b brown eumelanin
(K locus patterns are invisible on ee dogs)
K solid eumelanin colour
kbr reveals A configuration with brindled overlay. Results in brindle (sable with brindle overlay) and ‘dirty phantom’ (phantom with brindle overlay).
ky reveals A configuration
(pattern is invisible on ee or KK dogs)
a recessive black (recessive to phantom and sable, but causes no pattern in aa dogs; thought to be rare in poodles)
d light eumelanin, resulting in born blue (and presumably born café) dogs; thought to be uncommon in poodles
D dark eumelanin
S non parti
sp parti (white splodges on coat)
(these genes are theoretical and have not yet been mapped)
R darkens phaeomelanin in coat
r normal phaeomelanin in coat
These two loci are thought to account for the complicated spectrum of red and apricot dogs that can occur. From reddest to whitest and assuming no clearing or other dilution factors, these are:
RRcaca deep red
Rr caca red
Rr cacc light red
Rrcacw red that probably goes apricot on the legs and underside
rrcaca even dark apricot
Rrcccc probably apricot
Rrcccw apricot that lightens slightly on the legs and underside
rrcacc apricot that lightens slightly on the legs and underside
rrcacw apricot that goes pale cream on the legs and underside
rrcccw cream that turns white on legs and underside
(clearing -- blues and cafés are thought to be Vv, silver and silver beige VV, and holding black and brown vv)
(anomalies that don’t seem to fit current theory)
Some brown dogs from black parents are reported to fade similar to cafés even though there is nowhere for a V to come from. Some people have claimed they bred together two browns and got all black puppies, which would be impossible if both dogs were bb. It may be that there is a different locus, also recessive, that can produce brown eumelanin, and that this form of brown fades through some other mechanism.
Sable and phantom do not exhibit the dominance pattern most commonly quoted in the literature. I know of a breeder with two phantoms who regularly throw sable puppies, which would not be possible if ay was always dominant to at. There also exist dogs that appear to have both sable and phantom patterns. ayat seems to be variable, often producing a ‘shaded sable’ that holds its colour better in the dark phantom areas, but sometimes looking more sable or more phantom.