Reptile & Amphibian Forums

I'm seeing "Het. for XXX pattern trait" boa Morphs...cases that would indicate simple recessive genetics, if in fact "het. for" were the case.
Some of the morphs I'm referring to...I thought were Polygenetic, Codominant, or simply specifically bred lines.
Can I get some opinions on some of the genetics, primarily for the different "pattern" morphs on the market today?
A lot of these morphs have degrees of expression, so simple recessive doesn't make sense to me. Some have defined identifiable "Super" forms and some don't seem to.
Any help?
jsc
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"As hard as I've tried, just can't NOT do this"
John Crickmer

By definition, het is one normal gene paired with one morph gene.

So Motleys are either het Motley or homozygous (super) Motley for example.
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Thanks,

Dave Colling

www.rainbows-r-us-reptiles.com

0.1 Wife (WC and still very fiesty)
0.2 kids (CBB, a big part of our selective breeding program)

LOL, to many snakes to list, last count:
26.49 BRB
20.21 BCI
And those are only the breeders

lots.lots.lots feeder mice and rats

Yep exactly as Dave said. Now if you saw someone selling a normal looking boa that said "het for motley" you'd know they were full of it since being codominant, the motley trait will always be displayed.

That is exactly what I'm saying. You cannot have a Wild Type/Normal Looking Phenotypical Boa that is "Het. for XXX Pattern Morph", in the case of a Co-dominant Pattern Morph, can you?
jsc
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"As hard as I've tried, just can't NOT do this"
John Crickmer

This is where I think things get confusing (well, at least for me.) I think the term "co-dominant" is used too loosely. Might some of these patterns be a result of incomplete dominance rather than co dominance? If so, can the "dominance" of one of the alleles be so strong that the phenotype of a het could be so close to one of the homozygous phenotypes that it's difficult to tell the difference???? The classic example used for incomplete dominance is crossing a red with a white flower, where the result is a pink flower... which is obviously distinguishable from a red or white flower. But is it always that clear cut?? Can one of the F1/het flower's alleles be, let's say, 95% dominant, resulting in a flower very similar to either the red or white phenotype?

Great discussion.

Thanks,
Ed

>>That is exactly what I'm saying. You cannot have a Wild Type/Normal Looking Phenotypical Boa that is "Het. for XXX Pattern Morph", in the case of a Co-dominant Pattern Morph, can you?
>>jsc
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>>"As hard as I've tried, just can't NOT do this"
>>John Crickmer

At the level we are working at, codominant and incomplete dominant can be used interchangeably. (I prefer codominant because it has fewer letters to type.) Codominant is definitely used too loosely, mostly because many herpers have a wrong idea of the definition.

Nature is sloppy, so you get shades of gray rather than black and white. Humans make the black and white distinctions. Then we shoehorn Nature's results into the best fit (not necessarily a perfect fit) with our definitions.

Here's the ideal range of appearances with recessive mutant genes (I'd like to make the space in the middle bigger but can't.):
|--| |--|
The right |--| is for creatures with two recessive mutant genes, and the left is for creatures with two normal genes and creatures with a normal gene paired with a recessive mutant gene.

Here's the ideal range of appearances with dominant mutant genes:
|--| |--|
The right |--| is for creatures with two normal genes. The left is for creatures with two dominant mutant genes and creatures with a normal gene paired with a dominant mutant gene. This is the mirror image of the arrangement for the recessive mutant gene.

Here's the ideal range of appearances with codominance:
|--| |--| |--|
with the |--| on the left the range of appearances for a creature with two mutant genes, the middle for a creature with a mutant gene paired with a normal gene, and the |--| on the right for a creature with two normal genes.

Sometimes Nature is sloppy and gives an overlap:
|--|---|---| |--|
The |--| is the creature with two normal genes.
The |--|----|---| contains both creatures with two mutant genes and creatures wih a mutant gene paired with a normal gene. The salmon mutant gene in the boa constrictor produces this sort of overlap. It's not a perfect fit with our definition of either dominant or codominant. In such cases, I consider that calling the mutant a dominant mutant gene is a better fit than calling it a codominant mutant gene.

It's possible. See http://en.wikipedia.org/wiki/Penetrance

But as far as I know, nobody has confirmed incomplete penetrance in boa constrictors yet.

Paul Hollander

Duh..."penetrance". New word. I looked it up. Still lost.
You are agreeing with my statement and not being facetious? correct?

But there still is the question of whether or not a certain morph is Co-dominant. Here is an example -- "Jungle": Pattern anomaly genetically reproducible where there are degrees of expression, thought to be Co-dominant. Another of the same might be "Squaretail"

Is "Het for" possible with these pattern morphs in the case of a low expression or no expression individual?

jsc
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"As hard as I've tried, just can't NOT do this"
John Crickmer

I completely blanked on squaretails in my other reply. Squaretail is a Recessive trait though.
I'm probably not understanding your question again.
A low expression Jungle is still the Heterozygous version of the Jungle.
Just because we are unable to identify the expression of the trait,doesn't change the fact that it still has a Mutant Jungle Gene and a Wild type gene.
In spite of the right and wrong definitions. In our hobby "Het For" usually only is applied to a Recessive mutation. This recessive mutation Looks Wild Type but contains the Recessive mutant gene and a wild gene. Thus it is "Het For"
A Squaretail can be "Het For" Squaretail but not show the trait.
With a Jungle a low expression Jungle would still be Heterozygous.
I wouldn't call it "Het For" Jungle because you can't identify it as a Jungle therefore it becomes a Possible or Probable Jungle.Depending on how sure the producer of it is that certain trait defining characteristics are visible.
Hopefully this makes sense to you or gets to the point of your question.
. . . . Lar M
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Boas By Klevitz
Boas By Klevitz

This is not a joke.

You can have a wild type/normal looking creature that is heterozygous for a dominant or codominant mutant gene. For example, in humans, there is a dominant mutant gene that causes the possessor to have more than five fingers/toes on each hand/foot. Some humans have the gene without having extra fingers/toes. Such humans can give the gene to their babies, who may show the effect of the gene.

The usual explanation is that other genes and/or environmental factors prevent the gene from visibly expressing itself.

"Incomplete penetrance" is the technical term for such cases. It is not limited to dominant and codominant mutant genes. The term also applies to recessive mutant genes when they are homozygous but are not expressed.

However, in practical terms, there are a lot of crooks out there making bogus claims. So I would not buy such a snake.

Paul Hollander

For me this explanation of "Incomplete penetrance" seems easier to understand.
Although the finger toe trait your speaking of.
I heard of it but always thought it was a recessive trait.
I think the first time I heard of this was on X-files.
Then once again one of those Internet hoaxes claimed
Oprah Winfrey had this condition.
I thought in researching it I read it was recessive.
Its been awhile plus my source could've been and probably was inadequate.
As you warn Paul in the case of Reptiles /Boas if someone makes this claim,(penetrance condition)
walk the other way.LOL
Thanks for all of your insight Paul.
. . . . . Lar M
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Boas By Klevitz
Boas By Klevitz

You can't have a normal looking snake het for a co-dominate trait, you can how ever have it with a recesive trait. That baby might have been in a clutch where someone bred a co-dominat to a normal where half would be normal and the other would be the morph. The incomplete co-dominat is where there is no dominate morph visual like the hypo(salmon)gene, co-dominates with a dominate morph are like jungles or motelys, and recesive genes are all albino's in boa and also the stripe gene.

If you need more help with figuring out the genetics go to NERD's website and go to the care sheets link and then the genetics they help explain the simple recesive/double recesive and co-dominance.

>The incomplete co-dominat is where there is no dominate morph visual like the hypo(salmon)gene ....

There is no such thing as an "incomplete co-dominat". That quote describes a dominant mutant gene.

The people at NERD are top of the line breeders. They are not top of the line at explaining dominant and codominant mutant genes.

Paul Hollander

>By definition, het is one normal gene paired with one morph gene.

It's a bit more complicated than that. Heterozygous means that the two genes in a gene pair are not the same. Usually this means a normal gene paired with a morph gene. But it could also mean two different morph genes. An example of this is the paradigm boa constrictor, which has a Sharp albino mutant gene paired with a Sharon Moore caramel mutant gene.

Paul Hollander

D'oh,

Yup, close but no cigar!!!
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Thanks,

Dave Colling

www.rainbows-r-us-reptiles.com

0.1 Wife (WC and still very fiesty)
0.2 kids (CBB, a big part of our selective breeding program)

LOL, to many snakes to list, last count:
26.49 BRB
20.21 BCI
And those are only the breeders

lots.lots.lots feeder mice and rats

Great example Paul the Paradigm. I often wonder how many other possible non-wild or Dual Morph gene pairings are out there in the Boa world.
So Paul this dual mutant gene example would not be possible in a Homozygous Boa or Super form as in a true CoDom Boa like Motley or Jungle?
It just couldn't be possible right ?
Or have I missed something ?
. . . . Lar M
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Boas By Klevitz
Boas By Klevitz

>So Paul this dual mutant gene example would not be possible in a Homozygous Boa or Super form as in a true CoDom Boa like Motley or Jungle?

Such a dual mutant gene example is impossible in a homozygous boa. Because, by definition, when a gene pair is homozygous, the two genes are the same. I'm not sure what you mean by a "true CoDom Boa like motley". If you mean a boa with two copies of the motley mutant gene in the gene pair, then it is homozygous.

I picked the paradigm boa because it was the most likely to be familiar to readers of the boa constrictor forum. But there are plenty of other examples in a variety of species. And the two mutants do not need to be recessive to the normal gene. It's just that recessive mutants are more common than dominant and codominant mutants.

In the following gene pairs, the mutants are classed as dominant/codominant/recessive compared to the normal gene.

Heterozygous gene pairs that do not contain a normal gene:
Dominant mutant and dominant mutant -- example: A and B genes in the ABO blood type system in humans.
Dominant mutant and codominant mutant -- example: viable dominant yellow and dominant yellow in the lab mouse.
Dominant mutant and recessive mutant -- example: checker and barless in the domestic pigeon.
Codominant mutant and codominant mutant -- example: mojave and lesser platinum in the ball python.
Codominant mutant and recessive mutant -- example: dominant yellow and nonagouti in the lab mouse.
Recessive mutant and recessive mutant -- already covered with the paradigm boa.

Sorry I couldn't use more examples from reptiles, but there just aren't very many reptile genes with three or more forms (alleles). The lab mouse has over a hundred.

Paul Hollander

Such a dual mutant gene example is impossible in a homozygous boa period.
You have answered my question Paul thankyou
. . . . Lar M
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Boas By Klevitz
Boas By Klevitz

It is not possible unless its a motley to a hypo motley to get a hypo super motley like Jeremy Stone's premature one, but if you do the punnet square with 2 motley jungles bred together you would get 25% super jungles, 25% super motley, and 50% motley jungle.

>>punnet square with 2 motley jungles
25% super jungles, 25% super motley,
and 50% motley jungle
You have a good point it works on Paper.
. . . . Lar M
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Boas By Klevitz
Boas By Klevitz

I've got that. In your example are they on the same Locus? Or are they interchangeable on two different Loci?
Isn't that just as possible with other albino morphs, just not proved yet?
jsc
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"As hard as I've tried, just can't NOT do this"
John Crickmer

>I've got that. In your example are they on the same Locus? Or are they interchangeable on two different Loci?

Everything that I have seen about the paradigm boa is consistant with the Sharp albino mutant and the Sharon Moore caramel mutant having the same locus.

>Isn't that just as possible with other albino morphs, just not proved yet?

Absolutely. Multiple alleles are just as possible with other albino morphs and with nonalbino morphs like motley and arabesque.

Paul Hollander

>>Posted by: jscrick:Can I get some opinions on some of the genetics, primarily for the different "pattern" morphs on the market today?
I consider Arabesque a Pattern Morph- probably Dominant

Aztec- Pattern Morph and Color Morph as its developed -CoDom

Jungle I consider to be Color and Pattern Morph- CoDom

Motley I now consider to be Color and Pattern Morph-CoDom

Magma Boas- Stripe Pattern & color Morph Dominant possibly CoDom

Pearlescent Boa- Pattern Morph - Reverse Stripe Plus Pattern Anomalies-Genetics ???

Roswell - I would consider a Pattern Morph- Genetics ???CoDom maybe

Plus
Cyclone Pattern and Color Morph-Dom or CoDom don't remember

Abby Pattern and Color Morph-Dom or CoDom don't remember

MP Line possible Patterm and Color Morph-Genetic maybe??

CBLT Don't know any except Roswell

Two other Morphs I can't remember right now.
I think both are under raps still under development.

DaVincii is under development under raps,

There are probably more out there, these are what I can think of now.

. . . . Lar M
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Boas By Klevitz
Boas By Klevitz