I think it's called epistatic when one gene covers the expression of another. For example, I suppose a leucistic could still be a genetic stripe (as long as both mutations don't turn out to be the same gene) but I would expect the leucistic condition to hide the striped condition - if so, leucistic would be epistatic over stripe. I think genetic pastel albinos have been produced and if breeding proved them to be both homozygous albino and at least heterozygous pastel then that would prove that the two mutations where of two different genes. However, if you could tell by looking that it wasn't just albino (that it was also pastel) then I guess you couldn't say that pastel was fully hypostatic (the opposite of epistatic) to albino.

This would be different than what I suspect is happening with lesser and phantom from a few posts back. More breeding will need to be done to be sure but it looks like phantom and lesser may well be different mutations of the same gene - alleles. This is an important concept because a snake should only have two copies of the same gene (except perhaps females with genes on the gender chromosomes). In general one copy comes from each parent. If phantom and lesser are different mutations of the same gene then the karma has no normal copies of this gene and can only produce phantoms and lessers when bred to a normal (about 50/50 chance of each). A karma could also not give two copies of the same gene to the same offspring so karma X normal could also not produce karma. If lesser and phantom are mutations of different genes then both normals and karmas would be possible from breeding karma to a normal.

I once was told the proper term for having two different mutant versions of the same gene but I can't seem to remember or find it again. Does anyone here know the term for say a double het striped and motley corn snake? I understand that it's been proven that both of those mutations are the same gene and that motley is dominant over stripe so the offspring from homozygous stripe corn X homozygous motley corn look motley and that "double het" really isn't the right word for them but if you breed two of them together they produce 1/4 stripes and the rest look motley but only 1/4 of the clutch is really homozygous motley.

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