I have read a genetics article published in the ACBA Journal (American cavy club), written by Harry Claus, who I've been told are the "US genetics expert". The articles is about how to breed "fake" four coloured cavies. Check out a mosaic to see a truly multicoloured cavy!
The "fake" four coloured cavies, and sometimes even five coloured, bred by Harry Claus, are in fact three coloured cavies where one of the three colours have two shades. One of the three colours is white, the other colour is either red, yellow or cream, but he prefer to use cream. The third colour is either beige or lilac in two shades (two shades of beige or two shades of lilac, one cavy had three shades of beige!), he prefer beige.
What he suggests he has been doing is that he has found a new
mutation at the p locus, which he says is completely
recessive to the other known genes at the p locus
(P and p). He calls this gene pm.
In Sweden we have four different genes at
the p locus : P, p, pg and pr.
I do not know if we have pm or how it
would behave in combination with pg or
pr.
What I do know is that I have an
email friend in the US that claims to have the gene
pm on mice.
Anyway, Harry Claus says "I have raised beige and lilac cavies since 1963 and from 1983 to 1989 matings were made with animals that were two shades of beige or had two shaded parents of four shaded grandparents." He says that the results of these matings (232 young produced) is what he base his findings on. He says he has combined the two shaded beige or lilacs with tortoiseshell (epep or epe) and white spotting, thus he got his so-called "four colors".
One big problem is that he has 232 young, but only 25 of these were "nicely marked". And the fact that he says that "The two shades can vary from vivid to hardly distinguishable." This makes me think that there may be something wrong. If this gene really was the one he says it is he would have gotten more than 25 out of 232.
He also claims that he had to use cdcr instead of cdcd (actually he says ck instead of cd) but that is as far as I know the same gene (see note). This he does because the American standard does not allow a deep yellow colour. Here in Sweden we have the darker colour (deep yellow) in our standard, called buff, along with cream, and we know that many cavies that are genetically buff more resembles cream in colour. So from our point of view it would be unnecessary to involve cr and get cavies that will not breed true because they are heterozygous at the c locus. (Well, our creams are usually cdch instead of cdcr, but they look the same.) This genetical slip-up in fact (that he says he needs the cr) makes me less ready to believe that he knows what he is talking about. But of course, maybe these colours are not colourbred as hard in the US as ours are here in Europe...
"The best genotype would have to be Aa bb ckcr ePeP pmpm ss" he says. But I am not even convinced that he had pm, since we have seen a lot of two shaded beige and lilac coloured cavies here in Sweden that was just not enough colourbred. Simple as that! So from my point of view here in Europe he is breeding for shades of badly colourbred cavies which would never bee accepted as anything alse than pets here.
NOTE: Even Roy Robinson says in his book "Colour Inheritance In Small Livestock" that there are some doubt that both the cd and the ck both are present in the fancy-bred cavies. I suggest that since ck was first reported in the US that is may just be the name used there for the same allele that we call cd in Europe. Many cavies that are supposed to have ck gene have been imported to Sweden from the US and we have still not seen any ck. What have seen is that the US imports have cd which supports the idea that these alleles are one and the same.
Copyright Eva Johansson.
Last update: 25th of November 2002.