dog color genes (1)
The loci A, E and K
A: Agouti seriesThe A-locus controls the formation of dark pigment in the coat. In the past, it was thought that As (dominant black) was at the top of the A-series; however, recent research indicates that this color is in fact part of an other locus: the K-series.
Ay = dominant red, suppresses dark pigment into red with sometimes dark hairtips.
aw = wolf color, suppresses dark pigment into red and cream, the hairs have bands of red, cream and black. This color is not present in the Chow Chow.
as = saddle, suppresses dark pigment into red, but only in certain areas, so the coat is red, exept for a black saddle shaped part on the back.
This color is not a recognised color in the Chow Chow, although I have seen a photo of a Chow Chow colored like this.
at = black and tan, suppresses dark pigment into red as well, but in other areas so the coat is black, exept around the eyes, muzzle, chest and lower legs.
This color is not present in the Chow Chow.
a = recessive black, this is a common color in many mammals, and it is recently found to be present in dogs. It may be present in Chow Chows, as there are a few cases of blacks having been born from two red parents. An other explanation could be two red parents one of them is e/e, K/k and the other E/E, k/k, then a pup that is E/e, K/k would be black. But the e allele is not found in Chow Chows yet.
In the Chow Chow, only the allele Ay is definitely present; although it may be that the allele a is present as well.
E: Extension series
E = normal extention
Em = melanistic mask e = recessive red or non-extention, suppresses the dark pigment.
In the past some was thought that Ebr (brindle) was at the E-locus, but in fact it is an allele at the K-locus. The Em (mask) is certainly not the allele that couses the black mask in young Chows, because this mask in Chows fades away when they get older while Em stays dark. Although is was presumed for a long time, research has not found e in the Chow Chow breed.
In the Chow Chow only the allele E is present.
K: blacK series
K = dominant black
kbr = brindle
k = normal
In the Chow Chow two alleles K and k are present.
The loci E, K and A act together like this:
1 - if the E-locus is ee, the coat is red;
2 - if the E-locus is EE or Ee and at the K-locus is a K allele present, the coat is black;
3 - if the E-locus is EE or Ee and at the K-locus either kbrkbr or kbrk is present the coat is brindle, with the lighter stripes colored in the present A-locus color;
4 - otherwise, if the E-locus is EE or Ee and at the K-locus is kk, the A-locus determines the coat color.
In the Chow Chow rules 1 and 3 do not apply, as the brindle color is not a recognised color and there is no e present in the breed.
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this page was updated on October 6th, 2009 © Anita Meulstee |
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