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Ball Pythons and Incomplete Dominance

TripleMoonsExotic

TripleMoonsExotic

I <3 Stripes!
I remember having a discussion here with someone about how most Ball Python "co-dominant" mutations are actually incomplete dominant. I can't locate the original thread, but I thought I might be able to hook whomever the discussion was with by posting this. :D That and I'd love to hear other opinions!

So, my point in bringing this up is I'll be creating a Ball Python version of the Cornsnake Morph Gallery (after all of the bugs are worked out of the Cornsnake version) and I've brought up elsewhere should I continue the incorrect terminology trend or organize things correctly. So far their has been encouragement to use correct terminology and I'm game for it.

Now, does anyone see any of the Ball Python mutations as true co-dominant? If so, please post here and describe why you view it that way.





Just a refresher for those that don't recall the difference...

Co-Dominant - Expression of heterozygous phenotype resulting in hybrid offspring that resemble both parents equally for a particular trait (Hartwell, 2004). Condition in which the phenotypic effects of a gene’s alleles are fully and simultaneously expressed in the heterozygote (Klug, 2003).

Incomplete Dominance - Expression of heterozygous phenotype that is distinct from, and often intermediate to, that of either parent (Klug, 2003). Expression of heterozygous phenotype resulting in offspring whose phenotype is intermediate between those of the parents (Hartwell, 2004).

Reference

Co-Dominant - A relationship between two alleles where both are expressed when they are heterozygous together. When a codominant/codominant pair of alleles are shown in all three configurations, there are three resulting phenotypes

Incomplete Dominance - A type of codominance: a relationship between two alleles where both are partially expressed when they are heterozygous together. When such a pair of alleles are shown in all the configurations, there are three resulting phenotypes.

Reference (2007 Edition)
 
I know what the two terms mean. I'm speaking of its improper use.

The term "super" is frequently used for the third phenotype when referencing co-dom and inc-dom mutations. That is already known.

In your link it does state the one comparison that was brought to my attention in the previous discussion (that I still can't locate)...

red + white = pink (inc-dom)
red + white = red & white (co-dom)

For example, Mojave + Mojave = Luec which isn't a blending of the two or expressing both at the same time. Pastel + Pastel = Super which could be considered by some a blending of the two as it's basically a more extreme example of the Pastel.
 
TripleMoonsExotic said:
I know what the two terms mean. I'm speaking of its improper use.

The term "super" is frequently used for the third phenotype when referencing co-dom and inc-dom mutations. That is already known.

In your link it does state the one comparison that was brought to my attention in the previous discussion (that I still can't locate)...

red + white = pink (inc-dom)
red + white = red & white (co-dom)

For example, Mojave + Mojave = Luec which isn't a blending of the two or expressing both at the same time. Pastel + Pastel = Super which could be considered by some a blending of the two as it's basically a more extreme example of the Pastel.
Click to expand...


Actually IMHO the pastel would be the third phenotype or blending of the two. Super Pastel x normal = all pastel.
Mojave would also be the blending of the Luecy (aka Super Mojave)x Normal. In each of your examples there are only 3 phenotypes. Any theories on the carpet carpet question?
 
See, you're combining the genotype of the animals with the phenotypic desriptions.

BTW, Spider is the only one that I know of that COULD be co-dom. Otherwise, it's homozygous-lethal (also not proven, but it is the ONLY thing that makes sense for why we HAVEN'T seen a super... homozygous... gah! stupid trade names!).

Maybe it would be worth it to label the genes, and label ALL of them incomplete dom, and use the trade terms followed by the genetics?

For instance. Mojave (nM) and Blue eyed Leucy (MM) with "n" being identified as wild-type for each mutation.

Or, you could pick a, b, c, d, etc per gene set that uses a different locus.

Like c for the mojave/butter/lesser/het russo group. Although you would need like 4 pictures of the different Blue Eyed Leucies :)

That's the problem with the boid market... the larger number of dominant genes means that ANYTHING expressed in heterozygous form is identified as having a *super* form even though it's not, technically, correct.

Especially with the number of *designer combos* It seems like it would be worth it to identify the different loci, arbitrarily assign a wild-type and a mutation genetic symbol, and use that in conjunction with the trade name to provide some consistency.

Good questions, though, thanks. I love genetics discussions!
 
It's like mixing paints, red + white will make pink. Red doesn't totally block (dominate) the pink, instead there is incomplete dominance, and we end up with something in-between.

We can still use the Punnett Square to solve problems involving incomplete dominance. The only difference is that instead of using a capital letter for the dominant trait & a lowercase letter for the recessive trait, the letters we use are both going to be capital (because neither trait dominates the other). So the cross I used up above would look like this:



R = allele for red flowers
W = allele for white flowers

red x white ---> pink
RR x WW ---> 100% RW

The trick is to recognize when you are dealing with a question involving incomplete dominance. There are two steps to this:
1) Notice that the offspring is showing a 3rd phenotype. The parents each have one, and the offspring are different from the parents.
2) Notice that the trait in the offspring is a blend (mixing) of the parental traits.

The genetic gist to codominance is pretty much the same as incomplete dominance. A hybrid organism shows a third phenotype --- not the usual "dominant" one & not the "recessive" one ... but a third, different phenotype. With incomplete dominance we get a blending of the dominant & recessive traits so that the third phenotype is something in the middle (red x white = pink).

In COdominance, the "recessive" & "dominant" traits appear together in the phenotype of hybrid organisms.
 
Darc, were you the one involved in the original discussion? :)

Spider is Dominant from what I understood...As is Champagne, Coral Glow, Calico, Granite and Pinstripe.




Tom, you're right about Pastel. You got what I was trying to say and didn't get out right. :) With Pastel we have Normal then het (Pastel) then homo (Super Pastel) and Pastel would be the blend between Normal and homozygous. I also see how a Mojave is a blend between Luec and Normal though...Looking at things that way it makes loads of sense.

In your opinion, does a true co-dom BP morph exist? Maybe Yellowbelly?

As for the Carpet question...I would think that the Luecs would be the Homozygous (Super), if Jag x Jag is consistently producing these Luecs. If it doesn't consistently produce Luecs I would think something else is up. Though frankly I know zero about Carpets so I'd be the last person to ask! :D
 
Maybe? lol I don't remember.

Actually figuring out the genetics of most of these morphs is pretty easy.

Squaring the morphs with the trade names can get kinda hairy.

See, I was trying to help you come up with a way to list/describe ball morphs, some of which are on the same locus, and some aren't.

So, by those definitions, all of the ball morphs I can think of would be Incomplete Dominant, and spider may be just Dominant... Sorry for the confusion... :)

I can't think of one where wild-type and morph are EQUALLY expressed... and het russo and yellowbellies are still an intermediate form....

*goes and pokes ball websites again*
 
Well, the BP morph list will be organized much like the Cornsnake version is.

For example:

Single Recessive
* Albino
* Axanthic
* Caramel

Dominant
* Champagne
* Pinstripe
* Spider

Incomplete Dominant
* Butter
* Cinnamon
* Enchi

Then each individual once clicked on says something along the lines of:

Cinnamon. Also known as Black Pastel. Description coming soon.

Haven't decided what I'm going to do about the Dom/Inc-Dom combos yet...Didn't have to worry about it with the Cornsnake version! ;)

Someone was nice enough to provide me a list of about 200 bp morphs and combos (attached) so I don't have to think too hard. :D Fun part is me determining which are the same thing genetically. As far as the BEL's, I'll probably do what NERD does and put them all under one.
 

Attachments

  • MORPH LIST.doc
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TripleMoonsExotic said:
Darc, were you the one involved in the original discussion? :)

Spider is Dominant from what I understood...As is Champagne, Coral Glow, Calico, Granite and Pinstripe.




Tom, you're right about Pastel. You got what I was trying to say and didn't get out right. :) With Pastel we have Normal then het (Pastel) then homo (Super Pastel) and Pastel would be the blend between Normal and homozygous. I also see how a Mojave is a blend between Luec and Normal though...Looking at things that way it makes loads of sense.

In your opinion, does a true co-dom BP morph exist? Maybe Yellowbelly?

As for the Carpet question...I would think that the Luecs would be the Homozygous (Super), if Jag x Jag is consistently producing these Luecs. If it doesn't consistently produce Luecs I would think something else is up. Though frankly I know zero about Carpets so I'd be the last person to ask! :D
Click to expand...


I really don't believe that there is a true co- dom in the Bp. As far as I know spider & pinstripe have both proven to be lethal in the Homo (super)form.

The Jag x Jag does produce leucistics pretty consistently. Unfortunately none have survived yet.
 
BTW, Cinnamon is NOT also known as Black Pastel. They are two seperate genes, with two different *super* forms, and are allelic :)

Just so you know :)
 
Per NERD they aren't. Their super forms are identical (both solid, nearly black snakes). Personally I think they're just two different lines / selectively bred variations of the same morph (like Sunglow is to Amel) and instead of just sticking with one name they continued to pretend they were two different mutations. Evidently NERD is of that opinion too. :shrugs:
 
Well, super cinnies are frequently a solid REDDISH snake, while super black pastels are a solid DARK BROWN/BLACK snake, but they ARE allelic, and DO have different phenotypes.

Most breeders DO recognize that there is a difference.

But, that's up to you. :)
 
supercin_main.jpg


This'n looks pretty black to me... :shrugs:
(compliments of NERD from here)

Sounds to me it's not much different then them inappropriately using co-dom instead of inc-dom. ;)
 
Steph, honestly, not really in the mood to argue with you about it.

Now go look up a super CINNY and tell me it's the same thing.

It's a dark BROWN snake.

If something as simple as indicating that black pastel and cinnamon are DIFFERENT but ALLELIC isn't going to be on your page, then I'm not really sure what the point will be, and I won't use it.

Nice to have the discussion though, I would just prefer not to have this discussion with you per se... Doesn't ever really rub me the right way.

Good luck, and while you ask for opinions, you tend to just go ahead and do what you were planning on doing anyway, so I'll go ahead and back out now.
 
Darc, it's not an argument! It's a discussion about a difference of opinions. :)

The image and link I posted were NERD's Super Cinnies. They do have a "reddish" (looks more brown on my screen though) example up in that gallery, but they also have the dark brown and black examples.

Honestly, we can't know 100% of any of this without genetics testing. We do a lot of educated guessing! :) I am curious though...If Cinny and Black Pastel are just Allelic, why would they produce a Super? It's probable I'm missing something...

I think I might email NERD and ask them just to make sure what's listed on their website isn't a typo. It has been sitting up there for quite a while unchanged.
 
Ooooo! I think it is a typo!

I discovered another page on their website about Black Pastels and it states that the homozygous from Black Pastel is "dark, dusky black with a white, unmarked belly." In comparison the homozygous from Cinny is "solid-colored animal with a light, unmarked belly...rich cocoa brown to a dusky gray-black, depending on lineage" I'm starting to wonder if that's not the big difference between Black Homo and Cinny Homo! The belly!

Wish I could find an image that shows Black Super, Cinny Super and Combo Super..Both dorsal and ventral.
 
TripleMoonsExotic said:
I am curious though...If Cinny and Black Pastel are just Allelic, why would they produce a Super? It's probable I'm missing something...
Click to expand...

Because "super" is a silly term that doesn't really mean anything. A snake with two mutant alleles on the "cinny/black pastel" locus will be a dark, almost patternless snake - "super" almost makes sense when you're talking about two copies of one mutant allele (for example - "super pastel"), but no sense when you have multiple mutant alleles at one locus.

For example - a "blue eyed leucistic" can be a super mojave, a super butter, a super lesser. Or it could simply have two of any of the mutant alleles at that locus at which point the word "super" becomes useless.
 
Yes, I did state that "Super" is a term used quite often for homozygous co-dom/inc-dom. That's not where I was trying to go with that, sorry. What I mean is that (as an example) in the Amel/Ultra allelic example we have an intermediate homozygous. Why would the homozygous of two different genotypes produce an animal that looks like the homozygous of each of the genotypes in question. Boy, does that sound confusing! Let me try wording it differently. Why does Cinny Homo, Black Homo and the Combo Homo all look nearly identical if they are different genotypes? Does that question make more sense? :laugh:

I did email NERD for clarification on their gallery page and for their opinion. I'll post their response if and when I get one. :)
 
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