Even worse. . .
The ìcolorî allele (C) in cats allows whatever color and pattern is present to be expressed. Itís dominant to the albino allele, c. (This is another example of epistasis).
However, another allele of this gene, cs, causes whatever color is present to be expressedóbut only on the parts of the cat that are cooler than the rest.
This is an example of how the environment can affect gene expression!