Ultra question for the genetic wizard's

[drizzt_19]

I have been reading the threads concerning the Ultra gene...I was wondering if I am absorbing it all in the right way...

Is Ultra a co-dominate gene???That is what I have been picking up...If it is, how is it possible for a corn to be het for Ultra...I always thought that with co-dominate gene's they either had it or didn't have it...If they didn't display the gene they were not hets since it is a co-dom trait and is not transfered as a het trait...

Any help would be aprreciated...

 

[Clint Boyer]

I'll take a stab at it.

It is co-recessive. Well, maybe that's not the correct term but it is recessive to the normal gene but compatible with the recessive amel gene.

 

[drizzt_19]

Thanks Clint...I was wondering why things were not adding up...I thought I read somewhere that when you bred an Ultra to a normal you get half Ultra's and half normals...When you breed an Ultra to an amel you get half Ultramels and half amels...Guess that's where I was coming up with the co-dominate gene thing...

 

[Hurley]

The ultra gene is a recessive gene...to normal.

A snake carrying one ultra gene and one normal gene will look normal, just like amel. A snake with one amel gene and one normal gene will look normal.

So, by itself, it's a recessive gene, just like most of the others. If amel didn't exist, it would be just like all of our recessive genes out there.

Where the kicker comes is that it is an allele to amel. Any animal that is ultra/ultra, ultra/amel, or amel/amel is not normal.

Ultra is codominant to amel (not to wild type). When ultra and amel are combined in the same animal, you get something inbetween the two phenotypes. Ultramels look different than amels (you know how they look) and ultras (that look like a pretty typical hypo type of animal). They end up being "almost amel, but not quite" with dark ruby eyes and very little melanin.

 

[ecreipeoj]

I can certainly see why there is so much confusion with this gene. I have to look at it on paper to get it straight in my head. Ultra is recessive and Amel is recessive, so why is there a need for new genetics thinking? Ultramel and co-dominant is the reason and how it is passed on into the offspring compared to a regular recessive gene.

Lets start here:
Ultra Hypo = uu
Amel = aa
Ultramel = ua
Normal het Ultra = Uu (This has always been confusing to me. Why isn’t it Nu?
Normal het Amel = Aa (Again Na would make it much clearer)

So the reason we need to think differently than we have in the past with this gene is that at this locus there are three possible genes, but only two spots to fill up. In the past there was a normal gene and a recessive gene in every spot that a recessive gene had been found. (Striped/Motleys excluded)

A chromosome tree is kind of like a residential street. The locus is the different houses on the street, which have different addresses. The genes matches in these houses are like couples. If none of the couples are home, we have a normal snake.

At 100 Chromosome Lane lives the Lavender couple. When the husband is gone, we have the normal house and one recessive wife and the porch light is not on. The snake still looks normal. The same thing occurs when the wife is gone and the husband is home. When the Lavender couple is home, we have a homo Lav situation and the porch light turns on and it is purple and the snake looks Lav.

The Caramel couple lives at 200 Chrome LN, and the Anery A couple live on the next block at 300 Chrome Ln. All of the known Mutant Corn genes that we have discovered all live in different houses. Well, the Amel couple have been living at 1000 Chrome lane for 50 years and life has been very good.

The Amel couples wife’s sister and her husband the Ultras has moved into there house and there are now three possible genes at 1000 Chrome lane. The normal gene, the Amel gene and the Ultra gene, but only two genes are needed to turn on the porch light. At 1000 Chrome Lane we have these genetic possibilities.

Normal het amel (Na)
Normal het Ultra (Nu)
Ultramel het amel het Ultra (ua)
Ultra (uu)
Amel (aa)

There are only two spots that need to be filed up to turn the porch light on. If the Amel couple is home, the porch light turns on and it is orange, if the Ultra couple is home the light turns on, but is very dim it is kind of gray looking. If one Amel and one Ultra family member are home, the light turns on and the porch light is Ruby colored and we have an Ultramel.

If we can grasp how the porch lights are turned on, then we have to try to figure out how the genes that are causing the lights to come on are past on into their offspring. This is where the problem and confusion with Shivers “Ultra Ambers” has come in. The Ambers are a combo of the Caramels who live 200 Chrome Ln. and the Hypos who live at 400 Chrome lane and have nothing to do with the Amels, or Ultras at 1000 Chrome lane, but the Goldust do.

When we breed snakes, their offspring only get one gene from each house on Chrome Ln from each parent. Since only one couple is residing at all of the houses except at the Amel house everything at those houses is still simple recessive. At the amel house if Amel and Ultra are both home, either one of them can be passed into the offspring. It is not simple recessive any more, but it is still simple, we just have to adjust our paper work a little.

Breeding the Ultramels is the only thing that is different or Amel X Ultra.

Amel (aa) orange light X Ultra (uu) gray light = Ultramel (au) ruby light.

Ultramel X Normal, Normal het Amel, Normal het Ultra, Amel or Ultra will pass one (u) gene into half of its offspring and the other half will get an (a) gene. This is why the “Ultra Amber” line is unpredictable at this time. Nobody knows which Homo Caramels OR Ambers are het for Amel or Ultra. They can be het for either.

If the standard hypo gene was not in the mix, we could visually tell which Homo snakes we were looking at, but since the gene is in the mix. Nobody can tell a Regular Amber (hhcc) from an Ultra Caramel. (uucc) They also cannot tell a Hypo Ultra Caramel (hhuucc) from those two either. In addition any of the Caramels from this line not only can be het for amel OR Ultra they can be het for Hypo as well, so they are possible hets for amel, ultra or hypo, but nobody know which is which. Every Corn from Shivers line, can be het for Amel, Ultra or Hypo that are not homo for those traits. Match the wrong ones up and you will not get a Goldust.

I think the biggest kicker in this whole mess is that a Shivers “Ultra Amber” is a Goldust (uacc) but a Hypo Ultra Caramel (hhuucc), might look very similar, especially with Motley added in which lightens the entire combo as well. All we are talking about here is a very yellow snake with very reduced black pigment. I have looked at a lot of Amber and Caramel photos lately and they can be very light or very dark. I think a very light Amber could look similar to a Goldust from a very dark Caramel gene. There is just no way to visually tell which genes the YELLOW SNAKES are carrying from this line now, or which genes they are carrying as het. We can’t tell which adult yellow corns are Homo and/or het for what, and we really do not know what the hatchlings will look like or what their eye color will be either. When we get into the realm of double and triple homo corns, the eye colors can be normal, blue, ruby or pink that can change later.

I am not glad that I am on the outside looking in, because I wish I had some of these problems myself, but there will be many unknowns and confusion from this line for quite awhile.

 

[paulh]

A lot of herpers do not have the right definitions for homozygous and heterozygous. Check at www.dictionary.com, and you will see that the definitions do not say anything about what the animal looks like.

When a pair of genes are the same, then the animal is homozygous for that gene. When the two members of a pair of genes are not the same, then the animal is heterozygous.

So if a corn snake has a pair of normal genes, it is homozygous. It is also homozygous if it has a pair of amelanistic or a pair of ultrahypo genes. A corn snake is heterozygous if it has a normal gene paired with either the amelanistic mutant gene or the ultrahypo mutant gene. The snake is also heterozygous if it has an amelanistic mutant gene paired with an ultrahypo mutant gene.

The appearance of the heterozygous individual determines whether a gene is considered dominant, codominant, or recessive. So far, a corn snake that has any mutant gene paired with the normal version of that gene looks normal. That is the definition of a recessive mutant gene. Over the years, the definition of a recessive mutant gene has gotten combined with the definition of heterozygous in herping pseudogenetics.

FWIW, here is how to tell whether a mutant gene is dominant, codominant, or recessive (to the normal gene):
1. Recessive -- A heterozygous animal (with a normal gene paired with the mutant gene) looks normal. The mutant phenotype appears only when the mutant gene is homozygous.
2. Dominant -- A heterozygous animal (with a normal gene paired with the mutant gene) looks like an individual that has two mutant genes. The mutant phenotype appears when the mutant gene is either homozygous or heterozygous. This is the mirror image of the pattern shown by a recessive mutant gene.
3. Codominant -- A heterozygous animal (with a normal gene paired with the mutant gene) looks like neither the homozygous mutant nor the normal individual. The phenotype is dosage dependent. You can tell the genotype of the animal by looking at it, which is really nice for a breeder.

BTW, A codominant mutant gene is a codominant mutant gene whether a given individual has one copy of the mutant gene or two copies. And a dominant mutant gene is a dominant mutant gene whether a given individual has one copy of the mutant gene or two copies.

 

[Hurley]

Ultra Hypo = uu
Amel = aa
Ultramel = ua
Normal het Ultra = Uu (This has always been confusing to me. Why isn’t it Nu?
Normal het Amel = Au (Again Na would make it much clearer)

I'm guessing you meant to type Aa for normal het amel above.


If you are going to stick with one letter symbols for this, then the normal gene would be A since it's the amel locus.

From Serp's post:
Genotype/phenotype key:
AA (Normal)
Aa (Normal het amel)
Au (Normal het ultra)
aa (Amelanistic)
au (Ultramel)
uu (UltraHypo)

Using N would be confusing in that it makes it look like somehow there's a third allele, the N allele that is dominant at the amel locus. That is certainly not the case, so this is where I think a more standard notation is quite helpful. To rewrite Serp's listing:

A⁺/A⁺ (Normal)
A⁺/a^a (Normal het amel)
A⁺/a^u (Normal het ultra)
a^a/a^a (Amel)
a^a/a^u (Ultramel)
a^u/a^u (Ultra)

This way the locus is always listed (it's the amel -or albino- locus). Look to the superscript to see which version of the allele at the amel locus the gene is. A⁺ is a normal/wild-type gene, denoted by the '+'. The recessive mutant alleles to normal are the a's, a^u for ultra, a^a for amel.

Or in mouse notation, it'd be more like:
a⁺/a⁺ (Normal)
a⁺/a (Normal het amel)
a⁺/a^u (Normal het ultra)
a /a (Amel)
a /a^u (Ultramel)
a^u/a^u (Ultra)

...but it's so hard to see the wild type in that mess, that I prefer the method above.

 

[paulh]

...but it's so hard to see the wild type in that mess, so I prefer the method above.

Just look for the + character, and you've got the wild type allele.

Pity the breeders of salmon (AKA hypo) boa constrictors. Salmon is not a recessive, so they are using Sa//Sa⁺ for individuals with a salmon mutant gene paired with a normal gene.

 

[Hurley]

Ug.



Personal preferences. The lower case letter for normal makes it look (to me) like it's a recessive gene. If we had a third case, the middle case (vs. upper and lower), THAT'S the one I'd want for Normal. LOL It's the standard by which dominant, co-dominant, and recessive alleles are judged by.

 

[Clint Boyer]

Paul,
I see in your explaination the definition of dominant, co-dominant and recessive as they relate to the normal gene.

In the case of two 'recessive' genes being 'co-dominant' to each other, what would the proper term for that scenario?

 

[ecreipeoj]

It is co-recessive. Well, maybe that's not the correct term but it is recessive to the normal gene but compatible with the recessive amel gene.

I agree Clint. I didn’t see a term for that either. How can they be recessive to Normal, but co-dominant when the are combined which apparently they are not?

The dictionary may not consider what they look like, but I do and when I read your co-recessive term, it was perfectly clear to me.

We are making up names for the way the Ultramels look, perhaps the dictionary doesn’t care how they look, but since we do, what is wrong with making up terms that apply to the way they look? The English language is constantly evolving.

 

[ecreipeoj]

Normal het Amel = Au (Again Na would make it much clearer)

I'm guessing you meant to type Aa for normal het amel above.

I don’t have a clue what you are talking about Hurley? :shrugs: :santa: :cheers: Mistake corrected.

I see why we use A for the normal gene at the Amels house. The address should be 1000A Chrome Lane.

As far as the letters to the second power or with the + and or - symbols. I do not know how to do that on my word processor and it is perhaps not needed at this time for me to understand the concept.

Just wait until another couple like the “Sunsets” moves into the Lavenders house, and I will have to learn more.

 

[Hurley]

How can they be recessive to Normal, but co-dominant when the are combined which apparently they are not?

Thing is, recessive/dominance/co-dominance/etc. only applies to the relationship of 2 genes, not all three. In this case there are plenty of relationships, all are correct when applied to each combination.

Normal - amel : Dominant/recessive pair, normal being dominant
Normal - ultra : Dominant/recessive pair, normal being dominant
Amel - ultra : Co-dominant relationship, neither wins out and you get an animal intermediate between the two, both genes have some amount of effect.

Like I said, if amel didn't exist, ultra would be "just another recessive gene".

I don't know if there is terminology to describe the whole family here, besides amel and ultra are recessive alleles that are co-dominant to each other. :shrugs:

And yeah, I heard some mutterings somewhere about fun with sunsets. Can't wait to see how that evolves. You get too much fun out there in California.

 

[ecreipeoj]

And yeah, I heard some mutterings somewhere about fun with sunsets. Can't wait to see how that evolves. You get too much fun out there in California.

There seem to be a few “mysteries” that we haven’t answered yet. We just have another theory that we can apply to a situation and see if all of the pieces fit into the puzzle. If our old genetic rules don’t answer our mystery, then perhaps this new approach will. If it does then we wont be scratching our heads and in a state of confusion for 10 years.

There seems to be two good mysteries at this time. The Lavender Mystery still doesn’t seem completely solved, or at least it does not seem so. Chuck just emailed me with some ideas about the Motley and Striped locus. I am not convinced that we have that locus figured out as well.

 

[paulh]

In the case of two 'recessive' genes being 'co-dominant' to each other, what would the proper term for that scenario?

Two recessive mutant genes that are codominant to each other.

 

[drizzt_19]

Thanks guys and gals...Confusion cleared for the most part...I must of just read the post backwards...LOL...

 

[Jynx]

okay so if the ultra gene is co dominant with amel, has anyone figure out which other recessive genes its co dominant for as well? I've been trying to follow the whole ultra thing this entire time...its slowly sinking in.

 

[paulh]

The evidence we have indicates, but does not fully prove, that ultrahypo is a mutant gene that shares the same location (locus) in the corn snake genome with the amelanistic mutant gene and its normal allele. To be dominant, recessive, or codominant to another mutant gene, the two mutants in question must share the same locus. This is the first case in corn snakes where three alleles (amelanistic, ultrahypo, and their normal allele) may have the same locus. IOW, ultrahypo is not codominant to any gene except amelanistic.