This is what I don't understand about Ball Python Genetics

[EvesFriend]

Everyone always distinguishes between a 100% "normal" and a: Pastel, Albino, etc. I understand how those genetic traits come about that classifies these animals as such. However, I have a discrepancy with people saying there are many different variations of "NORMAL" Ball Pythons.

Obviously, the genetics account for these variations (or abnormalities) in these "normal" ball pythons. Surely, in regards to dogs in particular, you have heard of the "Mutt." A Mutt is not just a "fancy normal dog," it is a mixture of the genetics of two different pure bred breeds of dogs, or even a mix of many different breeds.

So, explain to me how a "normal" Ball Python can't be, say, 25% Pastel and 75% Normal.

[Jeo123]

The term is commonly called "het" short for heterozygous. It can't be 25%/75% because of the basics of genetics, you have two choromosomes, and you cannot split those into 4.

In some cases, traits are recessive, which means that if a BP is 50/50, it will be a carrier, but will not display the traits. Those snakes are probably the closest to the ones you're talking about. For a recessive, you would need to have both chromosomes with the trait in order for the trait to display.

I'm not familiar enough with all the BP dominance/recessive traits, but I believe the Spider trait is recessive. Therefore, if you mated a normal and a spider, you would get a snake that was 50% Spider, 50% normal, but it would appear to be normal.

If you mated one of these snakes with a pure spider, the resulting snake would not be 75% spider, rather it would either be 100% spider or 50%spider/50% normal because you get one chromosome from each parent. The spider only has two spider genes, so it definitely gives a spider, the normal parent either gives it's spider chromosome or it's normal one. That's how you get the results.

So hopefully that explains why it can't be 25% and 75%. 50/50 is possible though.

If any breeders want to correct me, feel free, I'm attempting to explain from a pure biology stand point without the specifics of BP traits.

[Aes_Sidhe]

Spider is a dominant morph so breading Spider to normal You have 50/50 percent to get spiders and normals...

[purplemuffin]

Pastel is a single gene, not a series of genes that makes it that way... So while you can have other genetic traits passed down from the parents that could be more or less like the other, that one single pastel gene either will be there or won't be there! (Or will be homozygous and will be a super pastel!)

It's less like a dog which is line bred, these are 'mutations' really

[Jeo123]

Ah, yeah like I said, I wasn't sure about which traits were dominant. Thanks for the correction.

[cinderbird]

The reason a bp can't be "25% normal and 75% pastel"

Based on gene ineritance, an offpsring gets a single copy of a given gene from the sire, and the other given gene from the dam. In the case of the pastel gene, lets say the sire is a pastel and the dam is a normal. The sire's two genes are Pastel and Normal (P and N). The females two genes are Normal and Normal (N and N). The sire can pass on either the P or the N gene, the female will pass on just one of the N genes.

IF the offspring inherits the P gene from the father, that overrides the normal gene and the animal expresses as a pastel since the pastel gene is a co dominant gene. If the offspring inherites the pastel gene, it expresses as a pastel. The reason that animal can still produce normals when bred to another normal is because at the gene location there is a second gene, the Normal gene (N).

Super Pastels have two copies of the P gene, so no matter what ONE of those P genes is getting passed onto the babies.

I hope my oversimplified version of gene inheritance helped!

[Adam Chandler]

Everyone always distinguishes between a 100% "normal" and a: Pastel, Albino, etc. I understand how those genetic traits come about that classifies these animals as such. However, I have a discrepancy with people saying there are many different variations of "NORMAL" Ball Pythons.

Obviously, the genetics account for these variations (or abnormalities) in these "normal" ball pythons. Surely, in regards to dogs in particular, you have heard of the "Mutt." A Mutt is not just a "fancy normal dog," it is a mixture of the genetics of two different pure bred breeds of dogs, or even a mix of many different breeds.

BP morphs are carried on a single allele, so either they get it or they don't.
So, explain to me how a "normal" Ball Python can't be, say, 25% Pastel and 75% Normal.

Different dog breeds have very different genetics. Different sizes, features as well as colors. Lots if different genes going on.
The only difference between and normal Ball Python and a morph is the the gene that deals with the pigment in their skin that produces color.
So basically when BP's breed the offspring will get one color allele from the mom and one from the dad. In the case where the dad is a Pastel either his Pastel allele gets passed or his Normal allele does.

If you want to learn more about basic reptile genetics I would recommend checking out this great post: http://ball-pythons.net/forums/showt...Basic-Genetics

[OhhWatALoser]

Well since there is over 100 base morphs and only a handful of them lay on the same locus (locus is where 2 alleles lay, you get one allele form mom, one from dad) There are at the very least 80 or so different loci controlling color we know about and i think it would be dumb not to assume there is many many more. "Normal" is a combination of those possibly hundreds of loci, while pastel just lays on a single locus.

[dr del]

Hi,

Everyone always distinguishes between a 100% "normal" and a: Pastel, Albino, etc. I understand how those genetic traits come about that classifies these animals as such. However, I have a discrepancy with people saying there are many different variations of "NORMAL" Ball Pythons.

Obviously, the genetics account for these variations (or abnormalities) in these "normal" ball pythons. Surely, in regards to dogs in particular, you have heard of the "Mutt." A Mutt is not just a "fancy normal dog," it is a mixture of the genetics of two different pure bred breeds of dogs, or even a mix of many different breeds.

So, explain to me how a "normal" Ball Python can't be, say, 25% Pastel and 75% Normal.

In those terms a normal BP would be the original "proto-dog" domesticated by man and a mutt would be what we call a combination ( or designer ) morph.

It's not a good analogy however as the look of modern dog breeds is the result of many, many genes and the different morphs of ball pythons are the result of a single mutated gene.


dr del

[Sammy412]

To make it a little easier.....

Dogs = snakes

poodles = ball pythons

You can compare dogs to snakes, but not dogs to ball pythons. You have to be more specific. So when dealing with breeding poodles, we'll say standard poodles for now.........you are breeding the same species, who have the same chromosomes.........black is a dominant color, white is recessive. so you want black puppies, you use a black mother or father. For a better chance of white puppies, you use both white parents, although either one could carry a different color trait as a recessive, but you've improved your chances of getting white puppies.


Make a little more sense now?