Genetics....

[paulh]

@paul Yeah that's what I mean when I say het Albino x het Toffee I am saying that Na x Nt = "at" which is a visual recessive gene Toffino. Kinda opened my eyes cause I naively thought all recessives required a homozygous for to show, and didn't even occur to me that recessive genes could behave the same as our co-dom/incomplete dominate (visual heterozygous) genes. So today was a breakthrough! Now to start a recessive project to find Allelic recessive genes out! LoL

Toffino is not a gene. Toffino is the appearance of a ball python that has a gene pair made up of a toffee gene and an albino gene. The identy of the genes and the identity of the snake's appearance are two different things. Another example of this is a ball python with a mojave gene paired with a lesser gene. The appearance of such a snake is blue-eyed leucistic.

If toffino was a gene, then toffino snakes would be able to breed true. But toffino mated to toffino always produces albino, toffino, and toffee snakes.

I looked up compound heterozygous. http://en.wikipedia.org/wiki/Compound_heterozygosity I am not too happy about using the term. Mostly because it is another piece of jargon for newbies to learn and misuse. NERD is expanding the meaning to any gene pair in which the two genes are not the same and neither gene is a normal gene. Which leads to confusion with visual het -- any gene pair in which the two genes are not the same and the creature does not look normal. IMO, it is easier to simply identify a gene pair by the genes -- lesser/mojave, normal/albino, albino/albino, normal/normal, etc.

I like the gene symbol system at http://www.informatics.jax.org/mgihome/nomen/gene.shtml (See sections 2.3 and 3.1 in particular.) The mouse geneticists have answered nomenclature questions than herper geneticists haven't imagined yet.

Gene pairs with two different genes that are both recessive to the normal gene have already turned up in several species of snakes -- reticulated pythons, corn snakes, boa constrictor, and others. There are hundreds of them in the lab mouse. I have no doubt that more will be found in snakes, eventually.