Please, not use the words "famille génétique" it is a stupid (french) invention.
All starts with knowing that all colorations of chicken-feathers consist out of ONLY two colour-pigments.
(Colour-pigments can be very much influneced by the acting or interacting or not-acting of several "reinforcers" and/or "diluters")
Black-pigment (eumelanin) and Red-pigment (pheomelanin) and the Absence of these two (we see as white).
The colour of our chickens is not determined by a single gene but of the actions of many genes together. The production of the genes is determined (or some just inhibit), in variable ways, the synthesis of the pigments is responsible for all the colours of our chickens.
The 2 colour-pigments (black & red) are expressing via the alleles of the E- & S-genes, the black pigments are the results of the action of the E-gene. This E-gene have different alleles, the original and 4 mutants by which are determinate the ground-colours.
If you want to know more I maded a file about the complete "basics of the chickens colours basics" with much illustrating photos :
[Modificato da Danny_57 21/08/2011 12:15]