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

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.

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.

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

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

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

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!

Quote:

---

Originally Posted by 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.

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

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.

Hi,

Quote:

---

Originally Posted by 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.

---

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

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?

In direct response to the "variations" of normal balls, yes it is genetics, but it is uncontrollable genetics.

Much like Piebald or paint horses. You can have a black and white paint mare and breed her to a black and white paint stallion. Even if all the foals are black and white paints, no two will look the same. They will all have varying amounts of black and white pattern. Some may even be deeper black like the mare, and some more grey like their sire.

This explains why you can own two dozen normal ball pythons and no two will look the same.

Now as far as actual morphs go, that is another story. Ball Pythons have two basic types of color morph, dominant and recessive. Dominant morphs only require one copy of the gene from either parent to produce offspring of the same type. However, the offspring either will inherit the gene or they won't. Meaning either they show the gene or they don't carry it.

Recessive genes are more complicated. It takes two copies of the gene, one from each parent, to produce offspring of the desired type. However, unlike in the case of dominant, some offspring will inherit one gene and some will inherit two. Those who have only one copy are said to be "het" and while they appear normal, they still carry that gene hidden in their blood. When bred to another ball who has a copy of that gene, you once again get the chance of the offspring getting two copies of the gene and thus being a visual morph.

As in the case of say, Ghost/Hypo balls. Ghost is a recessive morph. In order to produce more ghosts, you need one gene from the male and one from the female. Obviously the best odds come from breeding a ghost to another ghost. In this case, all the offspring will inherit two copies of the ghost gene and will be ghosts. However, if you breed a male ghost to a female who is het ghost, half of the babies will be ghosts, and the other half will be normals, but still carry the ghost gene. If on the other hand you breed one het ghost to another het ghost, things get more complicated.

Statistically, one out of four babies will be a ghost. Two out of four will be visually normal het for ghost, and one out of four will be nothing but normal. This gives rise to the term 66% het. In a clutch of four babies, statistically 2/3 will be het ghosts or 66% of the babies will be hets.

I hope I didn't confuse you even worse.

Gale

Quote:

---

Originally Posted by 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?

---

Beat me to it! I completely agree.