The cream dilution gene controls the amount of base colour dilution of a horses coat. This gene has a dosage effect where a heterozygous (used to describe a cell or organism that has two or more different versions (alleles) of at least one of its genes) cream dilution producing buckskin, smokey black and palomino; and homozygous (having two identical genes at the corresponding loci of homologous chromosomes) cream dilution producing cremello, perlino and smokey cream. (There is now a DNA test available to determine smokey cream, having been mistaken for perlino.)
|
No Dilution (nn) |
Single Dilute (nCr) |
Double Dilute CrCr |
|
Chestnut |
Palominio |
Cremello |
|
Bay |
Buckskin |
Perlino |
|
Black |
Smokey Black |
Smokey Cream |
The results of the about symbolic notation have the following meaning:-
|
CrCr |
Double Dilute. Horse tested homozygous for Cream Dilution (two copies of the Cream allele). Chestnut is diluted to cremello, bay is diluted to Perlino and Black is diluted to Smokey Cream. These colours can be further modified by the actions of other genes. |
|
nCr |
Dilute. Horse tested Heterozygous for Cream Dilution (one copy of the Cream allele). Chestnut is diluted to Palomino, Bay is diluted to Buckskin and Black is diluted to Smokey Black. These colours can be further modified by the ations of other genes. |
|
nn |
Non-Dilute. Horse tested negative for Cream Dilution. Basic colours are Chestnut, Bay, Black or Brown in the adsence of other modifying genes. |
