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Alright, I understand ball python genetics pretty well, but it took me forever to figure out what "co-dom" means since there are at least 3 different popular explanations I hear from snake breeders. Anyway, I know a mojave is co-dom and heterozygous, and a super mojave is co-dom and homozygous. A spider is dominant and heterozygous and so far there are no known homozygous spiders.

My question is: What is an example of a dominant homozygous ball morph? There is no super pin and no super spider, so is there such a thing as a super-anything that is just dominant and not co-dom?? Maybe I'm just missing something, but could it be that some dominant morphs are homozygous lethal?

Its my understanding that...

co-dom = visual that has a super.

dominant = visual with no super.

There may be homozygous dominant BP's out there if the spider and/or pinstripe traits are not homozygous lethal. That is there may be a "super" spider and pin, but they would look just like any old heterozygous spider or pin. The only difference would be the homozygous spider or pin would carry that trait for both alleles, so if bred to a normal the offspring would all be heterozygous dominant spiders and pins.

I am not sure how many people breed pin to pin or spider to spider and then raise the offspring to try to prove out a homozygous animal. Although people do that with regards to hypomelanistic boas. Hence the possible superhypo boas offered for sale.

Hypo boas were actually the only thing close to a "dominant homozygous" boid that I could think of. Just seems strange that there are no "possible supers" (possible homozygous) in the ball python world.

If someone did take the time to prove one out you would see more dom x dom breedings and more possible supers. But with the wobble problem, and the possibility of the trait being homo lethal I don't see many people currently willing to do the breeding to find out.

I think Kevin and Brian have done it for spiders and pins, unless I'm mistaken. Maybe someone else can chime in on that that was paying more attention to it than I did. Speaking of Brian I still need to check out yesterdays episode....

Are Champagnes dominant? And what about Pinstripes?

I have read on the websites of several breeders that they are, but (this is not meant to be a slander to breeders!) one can never be sure if they fully understand the term "dominant" gene.

Dominant: an individual with one copy of the gene has the same phenotype of an individual that has two copies of the gene.

So if Spiders were a dominant gene:
ss = Normal
Ss = Spider
SS = Spider (if SS isn't fatal, as some believe)
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Lincoln, NE
0.1 Pastel, 1.0 Pastel het Pied, 0.1 Pied, 0.1 Cinn, 1.0 Black Pewter, 1.0 Woma (hidden gene?), 0.1 Yellowbelly
2.0 Normals, 1.0 Thayeri, 0.1 Thayeri X Alterna, 0.1 crazy cat, 1.0 husband

Right, so that would mean that there should be "possible" homozygous spiders out there, and we keep waiting but no one has ever been able to "prove" a homozygous spider by producing ONLY spiders from that individual. You would think with all the spider combos that somebody should have found one by now that consistently only produces spider offspring. The same goes for all the other "dominant" ball morphs like pinstripes.

The way I understand it, a Dominate trait is just that, dominate. There is only one visual form of it, whether its het or homo. Just like your tyical normal ball python only has one visual appearance (even if there are tons of natural variations without thinking about morph traits). Thus Spiders are just another varient of 'normal' and are dominant. If a spider is paired with a normal animal, there is a 50% chance for each egg to be either a spider or normal animal.

If two spiders are paired up and assuming it isn't a lethal combination, you would just get 75% spiders though out of those spiders, there is a 1 in 3 chance its a SS spider. (ie a homo spider). But like normals, you can't tell any difference between a 'het' spider and a non 'het' spider.

Co-dominate shared dominace with other 'dominant' genes, thus when a normal ball python is paired with say, a pastel, half the offspring can be normal or pastel. Also, if the pastel is homo, you get a different appearing animal than a 'het' pastel. hence co-dominates have two visual forms.
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PHLdyPayne

That's exactly my point. If a spider is bred to a spider 3/4 of the offspring should be spiders, but those spiders SHOULD (hypothetically) be considered 33% possible "super spiders". The same goes for all the dominant ball morphs. It almost seems like they must all be homozygous lethal... it is hard to believe that nobody has found a spider that only produces spider offspring IF the SS homozygous spiders actually exist. Unless those animals have never been bred because of the wobbling. I guess that's my real question: does anybody know of a dominant homozygous morph that has been proven?

Pinstripe was effectively proven to be the only dominant ball python mutation I know of a couple years ago. Reptile Radio has an interview with BHB where he describes a normal looking pinstripe (presumably possible homozygous) that produced a large number of only pins for him. So you could start seeing possible homozygous pinstripes offered for sale like the possible homozygous spider adds years ago.

With spider we still don't know if it's co-dominant or dominant because no one has come forward with a proven homozygous spider to show us if it looks and acts the same as a regular spider. Don't know if that’s just because not enough spider X spider breedings (and breedings of possible homozygous spiders) or because spider is homozygous lethal. If spider is homozygous lethal I think that would technically be co-dominant because the heterozygous (live) phenotype is different than the homozygous (dead) phenotype.

I've not yet heard of eggs being hatched from champagne X champagne or desert X desert to even start to put those two to the test but I’m not in the loop on either morph.

Hah! I had the same thought about spiders being co-dom. If it's homozygous lethal I guess the live/dead thing makes them co-dom~

>I guess that's my real question: does anybody know of a dominant homozygous morph that has been proven?

Dominant mutant genes are less common in reptiles than in species that have been bred in captivity for dozens or hundreds of generations. Here are some, from an assortment of species, that fit the bill:

Boa constrictor -- salmon (often called a codominant mutant, but the difference between the homozygous salmon boas and heterozygous salmons is not clear cut enough for salmon to be a codominant mutant gene, IMO.)

Pigeons -- spread, checker, ash red

Cats -- orange, dominant white.

Mice -- viable dominant yellow, somber, others

Humans -- attached ear lobes, A and B blood types.

This list is just off the top of my head. Checking the reference books would turn up more.

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>>Humans -- attached ear lobes, A and B blood types.
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>>This list is just off the top of my head. Checking the reference books would turn up more.

sickle cell anemia
Tay Sachs
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AMAZON REPTILE CENTER

I think part of the reason we lack closure on the proving of homozygous dominate traits is simply because of the way we are doing things. When we have something new to work with, we don't know how the genitics operate. If the trait reproduces itself in the first generation, we as breeders are hoping that it is co-dom and has another, possibly more incredible, expression in the homozygous form. If enough eggs are hatched from het to het to indicate the lack of a 'super' form, attention goes elsewhere, and female dominate hets are then used to make other combinations. I don't know how many animals may have been produced from say Pinstripe to Pinstripe in an attempt to produce a super form, or if the were kept back by breeders or merely sold as regular Pinstripes... but I do know that most of us are not doing this in purely scientific and methodical fashion... and sometimes things just take way more time than they should. My gut feeling is that the lethal gene scenario would be the exception. However, the Spider, because of it's well known neurological issues, seems a good candidate.

Cheers,
Dan

Oi
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Brian Hettinger
480 Pythons
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You had to ask The answer is no, we have not determined whether it is dom or co-dom. I personally know of three small clutches produced from Calico to Calico breedeings, and have heard rumors of a couple more. All were during the 2007 to 2008 time frame. In 2008,Morton Wright produced an animal with extensive blushing that many of us believe may have been a Super Calico. Unfortunately that snake has since been lost. I too produced a possible Super Calico (visibly homozygous Calico) in 2008. Although the blushing on my snake is much less pronounced than the Morton Wright animal, she has quite a bit more than either of the Calico parents or the two Calico siblings produced in the same clutch. I don't know if anyone else has possible Supers that they hope to prove. I don't think anyone is breeding Calico to Calico any more - there are just too many other things to be done with them.

I think we may find that the different Calico/Sugar lines, are not necessarily lines at all, but that at least some of them are completely seperate genetic mutations, in which case we may be a long way from figuring this out. Next year I should have a shot at proving out my female poss Super. I also plan to breed my Super Pastel Calico male to a couple Calico females. I'm thinking that since the Pastel gene has such a crazy interaction with the Flora & Fauna line Calicos, it might really turn something on in a homozygous Calico... not sure it's logical or scientific... more of a gut feel.

Dan

What did Morton do to lose a snake. That was since the heist, wasn't it. Mike

Last year at Daytona the snake got out of a bag in a rental car and was never found.

I like the way your thining with that super pastel calico to calico breeding! And I belive your 100% on the different calico/sugar lines being different. Good luck on that female proving out this year! I want to get a pastel calico male from you later this season to put with a hypo pastave female in 2011... oh boy hypo calico pastaves!!
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Brian Hettinger
480 Pythons
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while reading this thread i noticed one mistake I think should be mentioned and corrected……
when using the Punnett Square, the abbreviations used for the specific traits should be used as the following….

Say if the letter “A” is used in terms of Albino….

AA = normal (in terms of Albino)
Aa = het (in terms of Albino)
aa = homo (in terms of Albino)

the lowercase letter is always used to represent recessive alleles, while uppercase the dominant. If a person unfamiliar with genetics/Punnett Square begins thinking two uppercase letters equals a homo visual….it will get confusing for them when in fact two lower case represents a visual homo.

In regards to dominants having supers of themselves….as Randy pointed out, I only heard of the Pinstripe. And to be honest not sure if anyone will “waste” a breeding trying to prove out dominants having a visual super of themselves…as this would take years to accomplish.

These days….most all if not everyone is trying to produce something “new” never seen before or at the least combos with the most common base morphs available. Two gene morphs will soon become the norm making triple and quad morphs availability so ever closer. If you stop and think about it....how long has the pinstripe and spider been out? Do you know of anyone even caring to do a pinstripe x pinstripe breeding? or better yet spider?

If you really want to get confused….try messing with mice genes…..

Pitoon

>>Alright, I understand ball python genetics pretty well, but it took me forever to figure out what "co-dom" means since there are at least 3 different popular explanations I hear from snake breeders. Anyway, I know a mojave is co-dom and heterozygous, and a super mojave is co-dom and homozygous. A spider is dominant and heterozygous and so far there are no known homozygous spiders.
>>
>>My question is: What is an example of a dominant homozygous ball morph? There is no super pin and no super spider, so is there such a thing as a super-anything that is just dominant and not co-dom?? Maybe I'm just missing something, but could it be that some dominant morphs are homozygous lethal?

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Mice are an excellent starting point for learning genetics. Then it's a piece of cake to move to snakes, once you learn the way herpers play fast and loose with the terminology.

Examples of bad terminology:

Dominant, codominant and recessive refer to mutant genes, not traits.

Super is herper slang for homozygous for a codominant mutant gene, homozygous for a dominant mutant gene, and extreme. An extreme version of a (fill in the morph) may or may not be homozygous for the gene. And some animals that are homozygous do not show the super appearance. This can be quite confusing, especially to a newbie.

Dominant mutant genes are rare (so far) in reptiles. They are more common in species that have been bred in captivity for dozens or hundreds of generations.

As others have written, if homozygous spider ball pythons die early and only heterozygous spider ball pythons mature, then spider would be a codominant mutant gene.

Paul Hollander

I was really only referring to ball pythons, not other species. The genetics aren't confusing at all, but rather the absence of dominant homozygous ball python morphs IS confusing. If two dominant recessives are bred together, 25% of the offspring should inherit matching alleles from the parent at the given locus so I guess it's just a matter of waiting to see which possible homozygous animals (a previous poster said Pinstripes are promising) prove out.

>If two dominant recessives are bred together, 25% of the offspring should inherit matching alleles from the parent at the given locus

Dominant recessives??? No such animal. From the context, it seems like the meaning is a snake with a normal gene paired with a dominant mutant gene. Such a snake would be heterozygous for a dominant mutant gene, just as a snake with a recessive mutant gene paired with a normal gene is heterozygous for a recessive mutant gene.

I put in a list of dominant mutant genes in species other than ball pythons to show that they do exist. It is just a matter of time before one shows up in ball pythons.

Obviously I didn't mean "dominant recessive". I've been talking about this so long that I typed the wrong thing, but I was still talking about dominant homozygous animals, but typed an honest mistake. Sorry.