Questions About Producing Super Ball Hybrids

[asplundii]

The amelanistic mutant gene in corn snakes tests as T-negative albino with the dopa test, but it is actually a nonfunctional version of the OCA2 gene. (T-negative means the gene is a nonfunctional version of the gene that produces the tyrosinase enzyme. OCA2 stands for oculo-cutaneous albinism 2.) So there you have two "T-negative" mutant genes that have different locations in the cell nucleus.

Small correction Paul; the T in T-neg is shorthand for tryrosinase which is the enzyme responsible for the very first step in the melanin biosynthesis pathway. A loss-of-function mutation to this gene causes the entire biosynthesis pathway to collapse as the process never gets started. The OCA2 gene (aka P gene), is actually a T-pos type mutant as tryrosinase is present in these mutants. The mutation is corn snakes was always just assumed to be T-neg but genetic evidence (I have not seen a DOPA-test in the literature but I have the genetic paper in my archives) showed this not to be the case. Further, OCA2 mutants still produce melanin but it is a defect within the melanocyte itself that prevents pigmentation.

I am not aware of any boa or python albino mutations that have had the dopa test or any other biochemical tests run. When used with boas and pythons, T-negative albino generally means no visible black pigment (melanin). T-positive albino means some melanin but less than normal. That leaves a good bit of room for error.

To the best of my knowledge the only genetic evidence we have for any snake "albino" is the corns. In everything else we just assume the classic yellow/white or red/white is a T-neg but, as the corns taught us, that assumption is potentially incorrect.

Is this true? I've always considered recessive and dominant to be relative to the gene it's paired with. So in a Ball, the 'fire' gene is dominant to the 'normal' gene therefore it's visual. But in the Ball to Blood hybrid, is it not possible for the Blood's 'normal' gene to be dominant to the Ball's 'fire' gene thereby making the 'fire' gene recessive in the hybrid animal.

This is true. If you think about it, the WT gene (or an ortholog of it) will be in each species because they have a common ancestor that had the gene. This is exactly the reason you can get an Albino BurmBall, both species carry the same albino type gene. So the Fire allele in balls will have a WT, non-Fire allele in bloods and you will see the incomplete-dominant effect. How exactly that is expressed would have to be seen but the effect will not be radically different as witness the Spider ball x carpet, the Jag carpet x ball, and the SpinnerBlast ball x carpondro. All of those hybrids exhibited mutant phenotypes that behaved exactly along the lines you would expect.