What Really Is Normal?

[rephibiankid]

Is normal dominate or recessive? Or what is it??? How come ALL (except anything het. for anything recessive) spiders are het. Normal, but NO normal can be het. Spider?? Why does the animal look the mutated gene if it has normal and that mutant gene in it? It acts recessive when combined with a dominate or co. dom. morph right? But then when mixed with a real recessive morph it acts dominate.

If you don't understand what I’m saying I’ll use an example... Okay so use spider. A spider has 2 genes affecting its skin right: 1 spider gene, 1 normal gene...Okay so why does it look spider if normal isn’t recessive its supposedly dominate isn’t it? (Or maybe it isn’t, maybe I missed something major??) Okay and it won’t mix to make a new morph, like combining a pinstripe and a spider will mix to make a spinner. But then when you have, let’s say a normal het. Pied, it has: 1 pied gene, 1 normal gene right? Okay so then in this case it acts dom. or co. dom.????!?!??!?!??!?!


Maybe I’m thinking to hard but this has really been bugging me and I need to know and can’t find any where that talks about normals here or anywhere!
If someone wants to respond and clear me up it'd make my day thanks!

[rephibiankid]

Also thanks to anyone who responds to help me! I have many more questions to ask you guys, but one at a time. But I will say I'll need someone pretty advanced in gentics.

[Egapal]

Is normal dominate or recessive? Or what is it??? How come ALL (except anything het. for anything recessive) spiders are het. Normal, but NO normal can be het. Spider?? Why does the animal look the mutated gene if it has normal and that mutant gene in it? It acts recessive when combined with a dominate or co. dom. morph right? But then when mixed with a real recessive morph it acts dominate.

If you don't understand what I’m saying I’ll use an example... Okay so use spider. A spider has 2 genes affecting its skin right: 1 spider gene, 1 normal gene...Okay so why does it look spider if normal isn’t recessive its supposedly dominate isn’t it? (Or maybe it isn’t, maybe I missed something major??) Okay and it won’t mix to make a new morph, like combining a pinstripe and a spider will mix to make a spinner. But then when you have, let’s say a normal het. Pied, it has: 1 pied gene, 1 normal gene right? Okay so then in this case it acts dom. or co. dom.????!?!??!?!??!?!


Maybe I’m thinking to hard but this has really been bugging me and I need to know and can’t find any where that talks about normals here or anywhere!
If someone wants to respond and clear me up it'd make my day thanks!

Normal quite simply means looking like the majority of wild Ball Pythons. Its also called wild type. The part that you are missing is that there is more than one gene that makes a BP look normal. A mutation in one gene will make an albino a mutation in another gene will make an axanthic (having two of the mutant genes in this case because these morphs are recessive). Because these mutations are for different genes (alleles) you can have a morph that has more than one mutation like an albino and axanthic makes a snow.

So to put it another way. A spider has the mutant gene that makes it a spider but it has the normal genes at other alleles so its not an albino or an axanthic.

[rephibiankid]

Normal quite simply means looking like the majority of wild Ball Pythons. Its also called wild type. The part that you are missing is that there is more than one gene that makes a BP look normal. A mutation in one gene will make an albino a mutation in another gene will make an axanthic (having two of the mutant genes in this case because these morphs are recessive). Because these mutations are for different genes (alleles) you can have a morph that has more than one mutation like an albino and axanthic makes a snow.

So to put it another way. A spider has the mutant gene that makes it a spider but it has the normal genes at other alleles so its not an albino or an axanthic.

okay so are you saying that its not dom. or co. dom.....its its own thing?....but I still dont understand why the spider gene will show up over the normal gene if it has both?

[Steveoo]

well with the spider or the pins its still got the "normal" type pattern just its reduced and thinner, if you look close enough to almost every basic morph you can find the "normal" pattern but its distorted in one way or an other. so its not that it isnt there just changed. imo, im no scientist

[shelliebear]

That's so funny--I was just wondering this last night XD
What I came up with to answer my own question was, for example, take the color red.
You don't combine anything to make the red; you bought it in the jar, already the color red.
Now, on the other side, you have blue. You bought it as blue.
But the manufacturer didn't have purple, and you want it. You pour half of the red color and half of the blue color in a separate container, and voila--purple.
It's kind of like, with morphs, they were bought from the manufacturer in the original or wild type pattern/color.
What happens with anything that is alive by the scientific definition of life is that it is subject to mutations in the gene at any point in time.
Diseases people are born with is one good example; they are born with a gene that was mutated (i.e. their parents were red and blue, but together made purple, which is an illness).
In BP's the "illness" can be, not an illness, but a color or pattern morph.
I hope I didn't confuse anyone. I love human genetics and am learning to convert it to BP genetics. But it's a little different.

[Serpent_Nirvana]

Normal IS recessive, or it can be.

"Normal" is, as has already been stated, nothing more than our term for what the majority of ball pythons look like when not expressing any mutant genes. In ball python lingo, "normal" is a phenotype -- a physical appearance -- that we use to mean that the animal is not expressing any mutant color or pattern genes.

When referring to specific genes (such as spider, albino, etc.) the "normal" gene on any given gene locus is more properly referred to as the "wild-type form." At each gene locus (again, such as albino, spider, etc.), there are two different alleles, one from mom and one from dad. An animal that is heterozygous ("het") at any given locus has a different allele from each parent at that locus. So, a het albino has one "albino" (mutated) allele and one wild-type (non-mutated) allele at the "albino locus."

Because on this specific locus (albino), wild-type is dominant to mutated, an animal with only one wild-type gene (a "het albino") will look "normal" (have a normal phenotype); you only get an albino-looking animal when you have NO wild-type alleles on the albino locus.

Pinstripe, however, is dominant to wild-type. This means that wild-type is recessive to pinstripe. If you have only one pinstripe gene, the animal will look like a pinstripe. If you have two pinstripe genes, (we think) the animal will still look like a pinstripe. The majority of pinstripes are heterozygous pinstripe, and also, technically, "het for normal (wild-type)."

Spider is also dominant to normal; if you have one copy of the "spider" gene, the animal WILL look like a spider. There is no such thing as a normal het for spider because if the animal had one copy of the spider gene, it would look like a spider, not a normal. Ditto for pinstripe, lesser, cinnamon, etc., etc..

As to WHY, on a molecular level, the spider and pinstripe genes are dominant to normal ... I have no idea. I don't think anybody knows, because this stuff has not yet been studied in snakes. (And if you do know, please tell us! )

I can tell you that, oftentimes, when a mutant gene is recessive to wild-type, that means that the animal can get by with only one copy of the wild-type gene producing protein. So for albino, you only need one copy of the wild-type gene to make enough enzyme to make enough melanin for the animal to look normal. You only see the albino form when there is no enzyme at all making melanin.

I hope that didn't confuse anyone more ... And for the other genetics geeks on here, YES, I oversimplified it. Apologies. (Yes I could talk about this crap all day long, thankyouverymuch ... )

[cstruthers]

Normal IS recessive, or it can be.

Hmmm... I dont really like this statement...

"Normal" is never recessive, it is co-dominate. Just like a large majority of the morphs out there.

Ill use pastel (co-dominate just like "normal) as an example, spider and pinstripes are not good examples to explain the normal gene because spider and pin are dominate not co dom. If you have a pastel, it has one pastel gene and one normal gene. BOTH of these traits are showing through. It doesnt look "normal" because it is mixed with the pastel gene. If you have a super pastel (so no normal gene at that spot in the DNA) so that means that there is no "normal" gene for the pastel to mix with, thats why you get a really bright snake. Because there is no "normal" gene mixing with the pastel gene. The analogy that shelliebear made with the colors is actually really good. If the traits are co-dominate (pastel, cinny, lesser, and a million others) then they mix with the "normal" gene because it is also co-dominate unless you have 2 of the same gene (super pastel, supper cinny, etc.) then the pattern does not mix with the normal gene.

So it is not recessive, you do see the "normal" traits in every co-dominate morph, just changed a little bit.

[Serpent_Nirvana]

Ill use pastel (co-dominate just like "normal) as an example, spider and pinstripes are not good examples to explain the normal gene because spider and pin are dominate not co dom

Actually, that's WHY I used those examples, and not co-dom examples.

I had a genetics professor (but one, of all the genetics I've had) who once explained that he doesn't like the terms dominant, recessive, co-dominant, etc., because he finds them misleading and because they're ultimately fairly meaningless on a molecular level. This was kind of a revelation for me; it definitely frees up your thinking when you can start to get away from the simple Mendelian constructs and that professor really got me to start thinking about these things in terms of their meanings and interactions on a molecular level.

Unfortunately, that's hard to do with BP genetics because we know so dang little about what's really going on with these guys. There's a lot that we can extrapolate from other species that have been studied, but there are NO reptilian models of development (AFAIK -- please correct me if I'm wrong) and half of what we do know even about MAMMALS has been elucidated through the study of zebrafish and chicken embryoes, and as useful and neato as that is, those animals are not ball pythons.

Also, these terms are fairly useful for thinking about simple Mendelian trait selection, which is what we're doing, for the most part (with some, unfortunately typically small, degree of selective breeding for more complex traits thrown in the mix). Sooo ...

All that having been said (I don't fault you if you've already bailed ... I type too much):

I agree with your explanation for "co-dominant" genes ... But I wasn't talking about "co-dominant" genes. (Which, as I'm sure you know, are really probably more correctly called incomplete dominant genes as far as we can tell.) I was talking about dominant genes, because that seemed to be what the OP was asking about.

In a true dominant mutation, like pinstripe, the wild-type form can be thought of as "recessive" because it is "hidden," in effect, by the mutant gene. (Unlike in incomplete dominant genes where the mutant and wild-type are essentially "mixing," as you said.)

Remember, the terms "dominant" and "recessive" as we use them here really describe the relationships of the phenotypes (appearance, in the case of BP morphs) conferred by the genes and not the gene itself. In an albino, the wild-type gene does not "dominate" the mutant (albino) gene such that the mutant gene is silenced; it just allows enough enzyme to be transcribed that enough melanin is produced that the snake looks normal. The presence of one wild-type gene "dominates" in terms of phenotypic expression, but not on a molecular level. (In the cases of some recessive diseases, enzyme or other protein titers can be used to identify carriers if a DNA test is not available.)

We don't know why, on a molecular level, the pinstripe mutation appears dominant over the wild-type appearance. Maybe it isn't 100% correct to call wild-type "recessive" to pinstripe, but the way the terms are used in current genetic parlance, if one allele is dominant, the allele is it dominant over must, by definition, be recessive. (Right? It has been [mumblemumble ] years since I took aforementioned genetics course.) Otherwise they would be classified as incomplete dominant.

As you say, the majority of BP morphs seem to be either recessive (in which case the wild-type is dominant) or incomplete dominant (in which case the wild-type is incomplete dominant as well) ... But if the mutation is dominant, as it is in a small handful of mutations, it seems to me that the wild-type must be recessive in those cases.

I apologize for the length of this post ... ... Back to clinical dermatology

[Egapal]

The important thing to remember is that normal is a term to describe the genes that make up your average wild BP. There are many different gene loci (locations) involved. When we say dominate, co-dominate or recessive we mean in reference to the normal gene. If you want to understand it more than that you should probably start doing some research on your own.