normal ball + norml ball = albino (is this possible?)

thanks guys. yeah i got her at a local pet store and they didnt have any info on her genetics. is there some sort of test that a vet could give her on her genetics? any ways ime gonna try some breeding with my friends bp in the next couple of years so lets cross our fingers. Ps. when i got her she was only $75 and at the other pet stores ball pythons that are het are along the lines of something like $150-250. so im doubting shes het but im praying she is.

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Originally Posted by kc261

Steve mentioned that BP breeders have basically lumped co-dom and incomplete dominance together. To be honest, I don't understand the difference between co-dom and incomplete dom enough to be sure if this is true or not.

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It is true, but they are very similar.

An incomplete dominant animal is one that partially expresses a certain phenotype. Let's assume the B* allele is incomplete dominant. If we breed two BB*, the resulting offspring options are BB, B*B* and BB* (or B*B).

Assuming the B allele makes a blue pigment, the BB animal will have dark blue pigment, the B*B* animal will have no blue pigment, and the BB* will have a lighter shade of blue.

The key to understanding the difference is in phenotypes. In incomplete dominance, the dominant allele is the only one expressed, but it's only partially expressed in heterozygous form. In co-dominant mutations, both the wild-type AND the co-dominant allele are expressed in heterozygous form.

This commonly occurs in flowers; pink flowers are often incomplete dominant for the red allele, although that's not always the case.

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Originally Posted by pythontricker

thanks guys. yeah i got her at a local pet store and they didnt have any info on her genetics. is there some sort of test that a vet could give her on her genetics?

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No. When a genetic test is done on a human, the sample is taken and tested against certain genes and chromosomes specific to the (usually) disease a person may have. For example, Huntington's disease, is traceable to one single gene (Htt). There are approximately 20,000 to 30,000 genes in the human body. That should give you a perspective on the odds of finding a specific genetic mutation randomly, especially in a ball python, given that very little genetic research has been done on them.

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Originally Posted by pythontricker

is there some sort of test that a vet could give her on her genetics?

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There is a thread about this right now.
http://www.ball-pythons.net/forums/s...ad.php?t=54943

Since you got her from a pet store, there is no way to know what she is. She could be het for something and the people who sold her to the pet store just didn't bother to pass along that information. Especially if she only had a low chance of being het, that is likely that info wouldn't be passed on to the pet store.

It is also possible she is CH or WC. If so, who knows what genetics she has. She might even carry something new that no one has seen before (extremely unlikely but possible).

The biggest problem is you have no idea what she'd be het for even if she is het for something. So if/when you breed her, you'll have to decide if it is worth it to breed her offspring back to her to try to prove something out, and how many years you'll devote to that. Even if she is het, her offspring will only have a 50% chance of het, so you'd have to breed at least 2 different sons back to her before you'd even be close to being confident she doesn't carry something.

In the meantime, you could be breeding her to a pastel or other co-dom and getting 50% morph babies each year. Or a super pastel or other super and get 100% morph babies each year.

I guess you can kind of do both at the same time by breeding her to a super something the first time, then each year after her babies get big enough, breed her to a different one of her sons and you'll still be getting 50% morphs out of her. But you'll also be inbreeding (or line breeding I guess technically) which should be avoided when possible, for an extremely small chance that she carries something.

Most people would say if you want to breed for morphs, buy snakes that you know carry the gene or at least a high % chance of being het. But there have been 2 stories on bp.net this year of people who hatched out totally unexpected morphs, so it does happen.

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Originally Posted by jhall1468

An incomplete dominant animal is one that partially expresses a certain phenotype. Let's assume the B* allele is incomplete dominant. If we breed two BB*, the resulting offspring options are BB, B*B* and BB* (or B*B).

Assuming the B allele makes a blue pigment, the BB animal will have dark blue pigment, the B*B* animal will have no blue pigment, and the BB* will have a lighter shade of blue.

The key to understanding the difference is in phenotypes. In incomplete dominance, the dominant allele is the only one expressed, but it's only partially expressed in heterozygous form. In co-dominant mutations, both the wild-type AND the co-dominant allele are expressed in heterozygous form.

This commonly occurs in flowers; pink flowers are often incomplete dominant for the red allele, although that's not always the case.

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Thank you for trying to explain this, but I'm still not sure what the difference is.

You give 2 examples of incomplete dominance which end up sounding basically like mixing paint together. Dark blue, no blue, or light blue in a het. Red, white (I assume?), or pink in a het.

Can you give an example of what co-dominance would be? I very vaguely remember something from junior high biology about roan cattle being a mix of red & white hairs. Would that be co-dom? Instead of each hair being pink? Which would be incomplete dominance?

In that case, is pastel technically incomplete dominance? Going back to the mixing paint idea, it is a little like someone mixed normal BP paint with the bright paint of a super pastel, and you end up with snakes with brighter color but not as bright as the supers. And if it were a true co-dom trait, we'd have spots that look normal and spots that look super pastel on a het version?

I know lots of the "het for white" morphs have lots of flames. So I guess this might be a true co-dom, with spots of white showing through? And if they were incomplete dominant traits, you'd end up with snakes that ended up looking pale or washed out evenly across the whole snake in the het version, possibly looking something like a hypo?

You can produce an albino from normals... except then they wouldn't be normals...

It is possible if the animals that you think are normal are actually het albino. That doesn't happen often though... :)

Justin

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Originally Posted by kc261

Thank you for trying to explain this, but I'm still not sure what the difference is.

You give 2 examples of incomplete dominance which end up sounding basically like mixing paint together. Dark blue, no blue, or light blue in a het. Red, white (I assume?), or pink in a het.

Can you give an example of what co-dominance would be? I very vaguely remember something from junior high biology about roan cattle being a mix of red & white hairs. Would that be co-dom? Instead of each hair being pink? Which would be incomplete dominance?

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My explanation sucked, for starters it wasn't complete, and secondly I actually reversed the definitions of the two. Let's hit this from another stand point. Let's say I breed an all black ball python to an all white ball python (let's assume for the moment, both of these traits are base mutations and neither are recessive).

If the alleles are co-dominant, the resulting ball python would be gray. This is the mixing of paint example that you gave. The proteins being produced by both alleles (in this case, pigment proteins) can only produce at about 50% the rate they should, so you have a total of 100% of the protein being produced.

If the alleles are incomplete dominant, the animal would be black and white. This is because each of the alleles is producing 100% of the protein. So the phenotype is a combination of the two.

The roan cattle is an example of co-dominance (but, just to add confusion to the mix, a roan horse is dominant).

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In that case, is pastel technically incomplete dominance? Going back to the mixing paint idea, it is a little like someone mixed normal BP paint with the bright paint of a super pastel, and you end up with snakes with brighter color but not as bright as the supers. And if it were a true co-dom trait, we'd have spots that look normal and spots that look super pastel on a het version?

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I can see why you would get to that point, because my explanation was really screwed up. But when the "paints mix" is co-dominant, when the paints are both displayed in the phenotype, but never mix, it's incomplete dominance.

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I know lots of the "het for white" morphs have lots of flames. So I guess this might be a true co-dom, with spots of white showing through? And if they were incomplete dominant traits, you'd end up with snakes that ended up looking pale or washed out evenly across the whole snake in the het version, possibly looking something like a hypo?

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Well, you are on the right track (had I not reversed the definitions in the first place you'd be dead right). The amount of the two incomplete dominant traits that show through is variable (and depends much more on environment than genetics).

Think of it as buckets of paint. Every ball python requires two gallons of paint to give a phenotype. If it's co-dominant, we mix the paints together really well and we have our phenotype. In incomplete dominance, we keep the paint seperate, but it's still only two gallons.

I looked some photos of Roan cattle, and I think the book is wrong. According to http://www.braunviehcenter.com/cattl...tics_part2.htm it is incomplete dominance, and that makes more sense given the photos of roan cattle are certainly the incomplete dominant phenotype. I'd guess the book was wrong on horses as well.

jhall

I think you had your explanation of incomplete and codom right the first time.

I can't speak for ball genetics, but can give you examples of human genetics.
Codom traits are traits where two dominant alleles are expressed together. A very good example of this is the ABO blood group. Blood types are controlled by 3 alleles, A, B. and i (being recessive to both A and B creating type O blood when the gene is ii). A person who has both A and B alleles will have type AB blood as both alleles are expressed TOGETHER.

Much like roan cattle, the two colors of hair are both expressed, not blended.

Incomplete dominant traits are traits where you have two dominant alleles at a loci but they are expressed in a blended form in the phenotype (this is sometimes also reffered to as intermediate expression). One example in humans is hair type. Hair is controlled by two alleles one for straight hair and one for curly. Someone who has straight hair is homozygous for straight (2 of the same allele). Someone who has curly hair is homozygous for curly. Now if someone has one straight allele and one curly (being heterozygous), it would present in the phenotype as wavy hair, with neither allele being completely dominant over the other, it would show as a blending of the two.

Another example of this is some flower colors (ie. carnations). If a carnation had one red allele and one white allele it would show as a pink carnation.

:):)

Are you sure you had it backwards the first time? After I posted my reply I was getting kind of excited that maybe I understood it and went and googled it, and based on the pages I looked at, I thought I was understanding which means you had it right the first time. Either that or I'm just lost beyond belief.

Here is a couple of pages that I thought explained it reasonably well:
http://users.adelphia.net/~lubehawk/...!/inccodom.htm
http://www.cod.edu/people/faculty/fancher/Dominance.htm

Some tips (sort of modified from the first page with my own embellishments thrown in) that might help remember which is which:
Co-dominance: co meaning together, like in co-exist. You have a third phenotype, but it isn't really something new, just the 2 traits together, side by side, peacefully. Red & white hairs on a roan cow.
Incomplete dominance: one trait tries to dominate the other but doesn't succeed, so they get in a big fight and end up with both of their guts all smushed together and smeared on the pavement. You have a third phenotype, which is what results when those guts get picked back up off the pavement, where they got totally mixed together. Pink flower.


I also found this page, which is a sort of quiz about genetics.
http://gbn.glenbrook.k12.il.us/acade.../Genetics.html
I didn't go through the whole thing and at least one link was broken, but what I saw looked ok. It had a note on one page that is interesting: "Both incomplete dominance and codominance genetics problems work the same way. The only difference is in the way the cell cellular machinery works out the phenotypic expression." (their typo, not mine)

This is why we can get away with lumping everything together into co-dom (or we could call it incomplete dom, it wouldn't matter). The Punnett square works out the same, the only difference would be the appearance of each phenotype which we just memorize what to expect.

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Originally Posted by Sunny1

jhall

I think you had your explanation of incomplete and codom right the first time.

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Damn I've made a bigger mess of this than I thought :P. You are right, I was right the first time... but I'm going to keep my mouth shut and let someone that knows what there talking about... do the talking:

http://users.adelphia.net/~lubehawk/...!/inccodom.htm