possible way to prove if butter and lesser are same or different morph?

[RandyRemington]

Alleles are an important concept for ball pythons now days because we are finding so many of them.

Basically, it's the idea of different versions of the same gene.

Most mutations are different genes all together. Take spider and pastel for example. When you breed a bumblebee to a normal you get that 1:4 chance of both bumblebee and normal because the spider and pastel mutations are on two separate genes and inherited independently. But it's important to remember that each mutation has it's own normal version (allele). Genes come in pairs (one from each parent) and at the spider gene location the bumblebee has one copy of the spider mutated allele and one copy of the normal for spider allele. Likewise, at the completely different pastel gene location (locus I believe is the term) it has two copies of that gene also; one with the pastel mutation and one normal for pastel. So which copies each baby gets is like two independent coin tosses. Once for the spider locus (spider mutation or normal for spider) and then again for the pastel locus (pastel mutation or normal for pastel).

Now consider the blue eyed leucistic gene. Rather than just having two versions, the normal/wild type allele and a single mutant allele there seem to be many different mutant versions. Why this gene can go wrong so many ways I have no idea but it looks like lesser/butter (may or may not be exactly the same), mojave, phantom/mystic (may or may not be exactly the same), Vin Russo, mocha, special, hidden, and probably some others I'm forgetting or that haven't been named yet are all different mutations of the same gene. Even though some of the combos aren't white (lesser + hidden = platy, mojave + special = crystal, phantom + phantom = super phantom, mojave + mystic = mystic potion) the breeding results so far support all of these mutations being the same gene.

An animal can't have more than two copies of the same gene. If you breed two lesser\\butter BEL's together each parent could only give one version of that gene, either lesser or butter (if they are even different), and no baby could end up with more than two copies of a single gene no matter how many different versions (up to 4) exist in the parents combined or in the species as a whole (many alleles in this complex).

But proving if two similar looking animals from different lines that breed true together are the exact same mutation or just alleles is very difficult. Many claim that there is a fundamental difference between lesser and butter so even if it's subtle there might be a difference between the mutation of that common gene between those two lines. Maybe there will be a combo that will show the difference more like maybe lesser + phantom (karma) will look different than butter + phantom? Or maybe they are the exact same mutation and initial differences between the lines where due to other genes in the founders like one being more high yellow than the other and soon it will be impossible to pick out which animals are lessers and which are butters.