Confused now???

[dprince]

Dominant morphs do indeed have a "heterozygous" form, that word does NOT only pertain to recessive genetics.

Exactly. :main_yes: Heterozygous simply means that an animal carries one gene for the trait instead of two, whether it be dominant or recessive.

 

[Paco]

Thanks I got it . But here is my issue. There is still no Homozygous Dominant Enigma and until proven out we cannot assume that there will be. Given what we Know about Dominant Homogyzous Lethal genes( I am trying to get some more specific statisics) maybe should assume that all Homozygous Dominant genes are leathal until proven otherwise. This is the feeling of many breeders. That would make more sense than to assume a particular trait will appear. IMO Also, There is no where on wiki thats say's that the Homozygous form the Enigma has not been produced and we are still waiting. I think thats very important information. Mainly for new Leo owners because they have no Idea that a Homozygous Enigma has not been proven and if you were to read that info not knowing this, you would assume that Homzygous Engima Exists and has been proven out. Which it has not. Thats where the confusion lies now. Not wheter or not it's Possible to have a Homozygous Enigma.

 

[dprince]

***

 

[GroovyGeckos.com]

At this point with no different looking homozygous "super" Enigma, we are rightfully assuming that this is a dominant morph. There really is nothing else it could be. We know it is not co-dom or inco-dom, and it is not recessive. So that is the only choice that is left IMO.:main_thumbsup:

 

[Paco]

Well I am learning a lot about this subject thanks to everyone who has replied so far. Very interesting stuff. There seems to be many Homozygous Dominant genes to date not as many in reptiles compared to mamals. As well as few Domiant Leathal genes as well. So I can see why everyone awaits the Homozygous Enigma. Only time will tell.

 

[Mel&Keith]

At this point with no different looking homozygous "super" Enigma, we are rightfully assuming that this is a dominant morph. There really is nothing else it could be. We know it is not co-dom or inco-dom, and it is not recessive. So that is the only choice that is left IMO.:main_thumbsup:

Well said, Dan. And yes, I guess only time will tell....so that we can be 100% positively certain. But for now I think we're about as close to certain as possible since it's such a new morph.

 

[Paco]

Here is some more info on Lethal genes for those who are interested. I asked Paul H. a Question about what appeared more often the Domiant Mutant Trait or the Dominant Mutant Leathal Gene. Here is his reply.


"It seems to me that you are asking which is more common -- dominant mutant genes that are lethal or dominant mutant genes that are not lethal.As far as I know, there are more dominant mutant genes that are not lethal. Most of the lethals are recessive or codominant to the normal counterpart. A dominant lethal would kill the possessor whether there was one mutant or two mutants in the gene pair. The mutant would immediately vanish from the gene pool. Though there are exceptions, like the mutant that causes Huntingdon's disease in humans. That kills people when they are in their 40s and 50s.

Codominant and recessive lethals can remain in the gene pool in heterozygous
individuals. If spider turns out to be a lethal mutant, it would be codominant
to the normal gene."

Paul Hollander
"

 

[godzillizard]

what about sub-lethals? could dominant mutations have sub-lethals that could become lethal in homozygous state? if an animal with one copy of a dominant mutation has abnormal issues, wouldn't the homozygous expression amplify those issues? I know they're co-doms, but take Mack snows for example--the one copy frorm has seemingly healthy genetics, but the pure super form has some hard to dismiss issues--difficult to get weight on them, short jaw/tails etc.

 

[Paco]

what about sub-lethals? could dominant mutations have sub-lethals that could become lethal in homozygous state? if an animal with one copy of a dominant mutation has abnormal issues, wouldn't the homozygous expression amplify those issues? I know they're co-doms, but take Mack snows for example--the one copy frorm has seemingly healthy genetics, but the pure super form has some hard to dismiss issues--difficult to get weight on them, short jaw/tails etc.

Brian... It's food for thought for sure, But if you read the entire thread I am afraid people don't really want to think about those possibilites until they happen. I got jumped on for bringing up the possibilty of a Homogygous leathal mutiation being involed in the Enigma. I found it to be very interesting information and information that many people know nothing about. As As I have seen from many of your post your grap of genetics is Excellent as well. I believe Paul H is a memeber here and his grasp of Genetics is Excellent hopefully he can add some more info to this.

 

[paulh]

what about sub-lethals? could dominant mutations have sub-lethals that could become lethal in homozygous state? if an animal with one copy of a dominant mutation has abnormal issues, wouldn't the homozygous expression amplify those issues?

From context, you are defining the word "dominant" as "not recessive". That would include both dominant (fully dominant) and codominant mutant genes. I just want to get that definition in here explicitly. It is one of the definitions of "dominant", but it confuses people who do not understand that.

As for the sublethal part of the question, the answer is yes. For example, the dominant yellow mutant gene in the lab mouse. The homozygous type dies before birth. The heterozygous type survives and can reproduce, but it has problems. It soon becomes obese, often develops tumors, and produces only a few litters before becoming sterile.

 

[Paco]

From context, you are defining the word "dominant" as "not recessive". That would include both dominant (fully dominant) and codominant mutant genes. I just want to get that definition in here explicitly. It is one of the definitions of "dominant", but it confuses people who do not understand that.

As for the sublethal part of the question, the answer is yes. For example, the dominant yellow mutant gene in the lab mouse. The homozygous type dies before birth. The heterozygous type survives and can reproduce, but it has problems. It soon becomes obese, often develops tumors, and produces only a few litters before becoming sterile.

Thanks Paul glad you joined the forum, your knowledge of genetics will be a great asset here.:main_thumbsup:

Now I am a bit confused about the definition you provided. Just to get things strait. So one of the defenitions of Dominant is used to describe Non Recessive Mutatuions and that include's Dominant and Co-dominant mutations. IS this correct? If so when would the defenition be used properly? Or what context ?

Now my next question is what exactly is a sub-lethal and how does it work or effect the host?

 

[paulh]

For simplicity, we can divide mutant genes into three categories: those recessive to the normal gene, those fully dominant to the normal gene, and those codominant to the normal gene. If we want to get complicated, we can divide codominant mutants into several subdivisions.

Recessive mutant gene -- When a recessive mutant gene is paired with the normal gene, the creature possessing the gene pair looks normal. It takes two copies of the mutant gene to make the creature look abnormal .

Dominant (fully dominant) mutant gene -- When a dominant mutant gene is paired with a normal gene, the creature possessing the gene pair does not look normal. A creature with one copy of the mutant gene in the gene pair looks like a creature with two copies of the mutant gene in the gene pair. (This is the mirror image of the definition of a recessive mutant gene.)

Codominant mutant gene -- When a codominant mutant gene is paired with a normal gene, the creature possessing the gene pair does not look normal. But a creature with one copy of the mutant gene in the gene pair does not look like a creature with two copies of the mutant gene in the gene pair. The genes in the gene pair can be identified just by looking at the animal, which is a boon to breeders.

Gregor Mendel divided all genes into two categories, dominant and recessive genes. In the 1920s, all genes were reclassified into wild type (AKA normal or standard) genes and mutant genes. The wild type gene is the gene at each location in the genome that is most common in the wild population. There is a wild type alternative to the enigma mutant gene, to the Bell albino mutant gene, the Mack snow mutant gene, and so on. Mutant genes are genes at each location in the genome that are not the most common in the wild population, such as the enigma mutant gene, the Bell albino mutant gene, the Mack snow mutant gene, and so on. A mutant gene is considered dominant, codominant, or recessive if it is dominant, codominant, or recessive to the wild type gene. The wild type is the standard of comparison, so cannot be dominant, codominant or recessive.

When a mutant gene is paired with a normal gene and the creature with that gene pair does not look normal, then the gene is either a dominant or a codominant mutant. When we know a mutant gene is not a recessive but we don't know whether it is a dominant or codominant, we just call it a dominant. Enigma in leos and spider in royal pythons are definitely not recessives. As we don't know whether enigma and spider are dominant or codominant to their respective normal genes, we just call them dominants and hope that the future will make things clearer.

A mutant gene is sublethal if it doesn't kill the possessor before sexual maturity but makes the possessor less likely to survive and pass on its genes in the wild than a normal creature is. Such genes can be dominant, codominant, or recessive to the normal version of the gene. There are too many ways to be sublethal than I can write. Bell albino in leopard geckos is a sublethal. Waltzing in mice makes the mouse spin in circles. Rex causes short, curly fur in cats, which is less warm in winter. Extra toes occur in a variety of mammals and birds and make it more difficult to walk. All can be considered injurious to health and survival if humans do not interfere.

 

[Crazygecko]

Great post Paul.

 

[godzillizard]

DITTO and Thanks Paul, for taking the time to word it with such eloquence...

 

[Paco]

DITTO and Thanks Paul, for taking the time to word it with such eloquence...

100% Agree and you make it so us Not so well versed can understand as well!!! Thanks Paul.:main_thumbsup:

 

[Franks_Geckos]

Great Post Paul.