What exactly is a Th. radix "Quad het"

[Cazador]

Once again, Kitkat has saved us from an oversight that I made concerning genetics. One could be 100% sure of having a het (AKA 100% het) by crossing a (homozygous) recessive individual (like an albino) with a 100% normal individual (homozygous dominant). Then all offspring would be 100% hets. One could also cross a (homozygous) recessive individual with a confirmed het. Then 50% of the offspring would be recessive (like albinos) or else they would be 100% het and have a normal appearance (phenotype).

If, however, you breed two hets, you get one aberrant homozygous recessive (e.g. albino), two hets, and one homozygous dominant, but the hets and the homozygous dominant all look alike. All one would know is that, statistically speaking, two of the three wild-type offspring would likely be heterozygotes, giving a 66% chance that they are hets.

A 100% het is certain to have one recessive allele (by definition). Thanks again, Kitkat .

In order to "design" a quad het, one would probably use two snakes that are double hets for different genes. If one crossed an anery x snow (double het) with an albino x (something else), they would produce a quad het, but this doesn't account for having a melanistic garter in the picture, unless it's unrelated. Also, as Kitkat mentioned, the wild-type is basically the opposite of anery, snow, albino, or whatever, and it is implied (but not counted) when you say you have hets.

Rick

[schlangenland]

Hi,
thanx for the interesting discussion. Scott Felzer answered me yesterday and here's what he wrote: "Quad hets are created from breeding Iowa snows to Nebraska snows. This cross creates anerythristics which carry the genes for Nebraska albino & snow, and Iowa albino & snow. Breeding quad hets to quad hets produces Iowa snows, Nebraska snows and anerythristics. Hope this helps.Scott"

Sincerely. Thomas

[Cazador]

That's no fair! He's assuming (unless he's tested) that the gene for the Nebraska albino lineage is different from the gene for the Iowa albino lineage. I don't know if the "snow" trait is controlled by a single gene or if it is the interaction of multiple genes, so I can't speak to that issue. By my way of thinking, an albino, is an albino, is an albino (at least as far as the single gene is concerned... homozygous recessive at a single locus). Isn't that fair to say? It's not my specialty, but something seems amiss.

Thomas... thanks a million for following-up on this.

[abcat1993]

Ugh, not genes again. Those poor, poor seventh graders.

[KITKAT]

Not to be defending Scott here... but it is POSSIBLE that the two albino strains are different.

I note that looking at the photos of the two albino lines Scott is working with, that one albino gene seems to mask the wild color of the snake more than the other strain.

Scott Felzer's Garter Snakes

Since I have not worked with either, I have no firm opinion.

I do know, however, why the melanistic genes are present in the Schuett strain. Schuett improperly thought that if he bred a melanistic to an albino, he would get snow. That is not how snow is made, and Kyle eventually sold the line to Scott Felzer, who had the anery gene to make the snows.

[drache]

I still find certain aspects of genetics confusing.
I do know that albinism, as a genetic trait, is separate from the genetics of species and sub-species.

[Daniel]

Hey guys,

just to put some things right: It is known and proofed that the two amelanistic strains Iowa and Nebraska aren´t compatible to each other.

Snow animals are created when breeding an anerythristic animal to an amelanistic animal and afterwards breeding the offspring to each other so you will recieve babys that are homozygot for anerythristic and amelanistic.

So, if you breed a so named quad het. to another quad het. you will recieve only three different colormorphs: 1. anerythrstics pos het for amel Iowa and amel Nebraska 2. snow Iowa pos het for amel Nebraska 3. snow Nebraska pos het for amel Iowa.

It isn´t really easy to answere the question of Schlangenland. If you want to give your snakes the right name, telling everybody, what genetic potential your snakes might have, you have to write down the long version. Thats the crux, when breeding animals to each other which do have a lot of het-gens.

Your snakes would have to be named: The normal looking: Thamnophis radix het for anery and amel Iowa, pos het for amel Nebraska.
The amel. animals would have to recieve the name: Thamnophis radix amel Iowa, het for anery, pos het for amel Nebraska
or
Thamnophis radix amel Nebraska, het for anery and amel. Iowa
And the snows: Thamnophis radix snow Iowa, pos het for amel Nebraska
or
Thamnophis radix snow Nebraska, het for amel Iowa

That`s it. You can´t summarize this with the addition that your babys are offspring from breeding quad hets. to each other. Especially because the parents aren´t quad hets. as you can see when reading the explanation of Scott Felzer.

Best wishes,

Daniel

[KITKAT]

Scott writes that when he bred his Iowa albino to his Nebraska albino, the result was wild colored Plains.

Therefore, one of those genes is a true albino, while the other one is something else... but also apparently, both traits are recessive.

[Cazador]

Hey Daniel,

Thanks for the info. I guess the point of whether the Iowa and Nebraska amel genes are different alleles is a moot point then. I'm almost afraid to mention this, but if they're reproductively isolated from one another, that means... by definition... they're different...

but I don't want to get all wrapped around that issue. It's not worth debating these, essentially lab-produced anomalies that would have an extremely small chance of mating in the wild. In a way, it's a shame that this issue is even arising in the garter snake world .

Rick

[adamanteus]

Yes, indeed!