Stupid Question..

[HOFSKC]

I think you are a little confused on the dominant thing.

Spider is a dominant gene. This means that the heterozygous form and the homozygous form look exactly a like and you cannot tell the difference between the two. Most spiders you see for sale and that are produced are heterozygous animals.

Woma is a co-dominant gene. This means that the heterozygous form looks different from the normal and the homozygous. In the case of the woma the homozygous form is called the pearl and it is supposidly (sp) lethal with all babies dying in the egg or shortly after they emerge (as you stated).

All and all they are two different genes that produce similar looking animals in their heterozygous forms.

I believe you are getting these two terms confused with recessive genes. To my knowledge there has never been a dominant Spider produced. Let me be clear, a dominant Spider would be like a Super Pastel in that breeding a Super Pastel to anything other than a Pastel would produce all visual Pastels. So if you bred a Super Pastel to a Spider you would produce an entire clutch of Pastels, however half of them would be Bumble Bees since the Spider gene is Co-dominant.

This is not to say that you couldn't luck out on the odds and produce an entire clutch of Bumble Bees but in most cases since the Spider gene is Co-Dominant you would more often than not get half and half.

The Woma gene however does have what is believed to be a Dominant or "Super" form. To my knowledge the idea that it is Dominant is purely speculation since I don't know that anyone has ever raised one up and breed it to prove this theory out.

Layman's Definitions
Homozygous - The visual state of a particular gene or trait
Heterozygous - The state of a recessive trait in it's non homozygous (visual) form
Dominant - A gene that supersedes the natural appearance
Co-Dominant - A gene that is equally available in appearance as the natural appearance

[Serpent_Nirvana]

I believe you are getting these two terms confused with recessive genes. To my knowledge there has never been a dominant Spider produced. Let me be clear, a dominant Spider would be like a Super Pastel in that breeding a Super Pastel to anything other than a Pastel would produce all visual Pastels. So if you bred a Super Pastel to a Spider you would produce an entire clutch of Pastels, however half of them would be Bumble Bees since the Spider gene is Co-dominant.

This is not to say that you couldn't luck out on the odds and produce an entire clutch of Bumble Bees but in most cases since the Spider gene is Co-Dominant you would more often than not get half and half.

The Woma gene however does have what is believed to be a Dominant or "Super" form. To my knowledge the idea that it is Dominant is purely speculation since I don't know that anyone has ever raised one up and breed it to prove this theory out.

Layman's Definitions
Homozygous - The visual state of a particular gene or trait
Heterozygous - The state of a recessive trait in it's non homozygous (visual) form
Dominant - A gene that supersedes the natural appearance
Co-Dominant - A gene that is equally available in appearance as the natural appearance

Sorry but ... I think your "corrections" to her post are a bit less correct than her actual post. I wasn't gonna butt in and get all technical (lord knows I doubt anyone even reads all of what I type), but .........

I know that you acknowledge that you're making up "layman's" terms, but the word "homozygous" does NOT refer to the visual state of a gene or trait. It means that, for a given gene locus, that animal has the same exact allele on each chromosome -- which, in "layman's terms," would mean that the animal has "two copies" of the gene of interest.

By your definition of "homozygous" to mean "expressing a trait," a regular (non-super) pastel would be "homozygous pastel," which, no offense, is flat-out wrong.

"Heterozygous" means that, for a given locus, the animal has two different alleles on each chromosome -- in "layman's terms," that means that it has "one copy" of the gene of interest. Pastels (non-"super"), Enchis (non-"super"), all spiders and all pinstripes (as far as we all know) are heterozygous for their respective mutation genes.

Yes, non-visual "normal" looking animals that are heterozygous for recessive traits (AKA "hets") are also "heterozygous." And indeed, the visual forms of those recessive traits are "homozygous." However, there are definitely visually expressing heterozygous animals (like regular pastels).

Your "layman's definitions" of dominant and co-dominant are a bit more "right," but your explanation in the text is, again, wrong. (Sorry. )

The terms "Dominant," "Co-dominant" and "Recessive" refer to the way in which one gene behaves with regards to another gene -- in this case, the gene of interest is whatever morph gene and the "other gene" is the wild-type.

The spider gene is dominant to the wild-type gene, because an animal that carries both the spider gene and the wild-type gene expresses the spider gene -- it looks like a "spider." If spider were not dominant to the wild-type gene, you could have an animal that carried the gene but looked like a normal -- ie, a "het spider." There are no "het spiders," and we know that breeding a spider to a pure wild-type produces spiders; we therefore know that spider must be dominant.

(Now, to my knowledge there has never been a homozygous spider produced ... But spider is dominant, based on its mode of inheritance.)

The term "co-dominant" is used in snake breeding to refer to a gene that "blends" with the wild-type in its heterozygous form, and has a different looking homozygous form (a "super.") So, pastel is considered "co-dominant" because a heterozygous pastel looks different from a homozygous pastel.

The difference between a true dominant and "co-dominant" is that a true dominant gene looks the same in its homozygous and heterozygous forms. (Like Kelly said ) I've heard rumors that the pinstripe is "true dominant" (supposedly somebody out there has a pinstripe that only produces pinstripes, suggesting that it is homozygous for pinstripe, but I can't substantiate that in any way). I don't know of any other mutations of ball python that are true dominant.

I don't know whether woma (regular-style) is true dominant or co-dominant.

"Hidden gene" woma is co-dominant, but the homozygous form is lethal (pearl).

Spider is thought to be co-dominant with a homozygous lethal form that dies in the egg, but AFAIK nobody really knows and it might just be true dominant and not enough breedings have been done to identify that homozygous spider.

I know it's all just semantics, and probably that was all mega-overkill, but I think it's important to all try and use the same words to describe the same things -- otherwise it gets even more confusing than it already is O.o

Sorry that was so horribly long-winded.

[HOFSKC]

After reading this I agree that I was wrong, I was saying the same thing just mixing up my terms. Thank you for the clarification.