The Dominant White gene (I) is an autosomal gene capable of inhibiting the development of black pigment in plumage. In the case of Dominant White, the genes necessary for black pigment are present but do not manifest themselves due to the inhibiting action of the Dominant White gene. Pigment is formed by melanocytes in feather germs, but there is a nontransfer of pigment by melanocytes to keratinoblasts.
Some Ameraucana enthusiasts are working with a project color that results from a single copy of the Dominant White gene on Extended Black. A few breeders have asked for a breeding chart to use while working with the project color. Here you go!
The Dominant White gene produces the following:
1. A white homozygote (I/I) which results in a white phenotype
2. A heterozygote (I/ I+) which results in a black-flecked phenotype
3. A homozygous recessive (I+/I+) which results in a black phenotype.
Modifying genes, which limit or expand the amount of black on a Dominant White heterozygote, affect the overall number of black feathers present on the plumage. The modifying genes also affect whether the black plumage feathers will be solid black and the white plumage feathers solid white.
Hopefully this breeding chart will be helpful to breeders working with the project color!
*Please note that all names that breeders presently identify the project color as have been listed merely as a means to appease all breeders.
