D-Locus Cat (Dilution)

D-Locus (Dilution)

The Dilution gene, also known as the D-Locus, corresponds to the gene for melanophilin (MLPH) which plays a role in pigment distribution. Mutations at the D-Locus lead to a ‘dilution’ effect on the eumelanin (black) and phaeomelanin (red/yellow) pigments in an animal’s coat. Affected animals exhibit a lighter or diluted coat coloration.

The dilution of eumelanin results in a blue nose and coat colours that range from silver to almost black (such as blue, charcoal or silver coats), while the effect on phaeomelanin pigment causes it to appear pale or cream-coloured. Specifically, chocolate/brown/liver hues (influenced by the B-Locus) dilute into lilac, light tan, or isabella tones.

Inheritance

The D-Locus features two alleles: D (dominant) and d (recessive). Animals homozygous or heterozygous for the dominant D allele (DD or Dd) display a normal, non-diluted coat coloration. Conversely, animals homozygous for the recessive d allele (dd) showcase the diluted or lighter coat coloration.

Relevant tests

• K760