This article was first written by Eddie Crutchley in 1998 as part of a supplement to the NCS gazette.
INTRODUCTION
In the example mating illustrated, letters were used for simplicity. It is therefore necessary that we choose letters as symbols for each of our colour types in order that this simplicity is maintained.
It is standard practice for small case letters to be used for recessive characteristics and that capital letters are used to indicate a dominant characteristic.
As I have indicated in an earlier article on this topic ,there is no accepted standard for these symbols and it is up to you to use a method which you can remember readily. The symbols which I use are as shown;
DOMINANTS
Black Velvet - BLbl
Wilson White - Ww
Heterozygous Tower Beige - Bb
Homozygous Tower Beige - BB
Extra-Dark Ebony - EEEE
Dark Ebony - EEEe
Medium Dark Ebony - EEee
Medium Ebony - Eeee
Standard - eeee
(Kits born from Ebony parentage which resemble Standards should be refered to a 'Light Ebonies' in case they are Medium Ebonies with one Ebony gene, which does not show itself. This listing for Ebony assumes four cumulative Dominant genes at work.)
RECESSIVES
Homozygous Sapphire - ss
Heterozygous Sapphire - Ss
Homozygous Violet - vv
Heterozygous Violet - Vv
Homozygous Charcoal - cc
Heterozygous Charcoal - Cc
At this point it should he stated that of the colour mutations so far discovered, each pair have different locus points, indeed no two colour genes are on the same chromosome. Thus the genetic code for a heterozygous Wilson White would be Ww where W is the dominant gene for white and w is its standard allele shown as recessive. Similarly a heterozygous Std/Charcoal would be Cc, C for the standard and c as its recessive allele. In fact this is only an abbreviation of the genetic colour code for these animals since we should give the complete picture for the Std./Charcoal as Cc, bb, blbl, ww, SS, VV, and more if all the less common mutations were included. For instance;
A Black Velvet Violet Carrying chinchilla would be known as BL bl V v, rather than BL bl V v w w b b SS CC eeee, since listing the code for Beige, Sapphire, Charcoal and Ebony is pointless, since it is not present...
It is superfluous to use all six locus codes when only one code is pertinent and so it is usual to write only the codes for the loci in question.