Howís it work?
BUT. . . for any of these patterns to be seen, the agouti gene must be present.
- A non-agouti cat (aa) will have tabby genesóall cats doóbut never show them.
This is epistasisóone gene affecting how others are expressed in the phenotype.
- You could think of it like this: there must be a dominant agouti allele to ìswitch onî the alleles for the tabby pattern.
- Both the agouti and the tabby genes affect the expression of the base color genes (black, brown, orange, etc.)