Can you have a het for a co-dom gene?

[Big Jamie]

As above, can you have a snake het for a co-dominant gene?
For example, tiger retics are heterozygous for the tiger gene and a supertiger is the homozygous form, am I right?
I didn't think you could get a normal het tiger as I've never seen anyone with one and if you bred a tiger to a normal you'd get normals and tigers right?

So if anyone could clear up this question for me it would be appreciated and maybe another example could help.

Thanks,
Jamie

[quadrapop]

when they say het tiger, it means it is a tiger but they are being specific with the word heterozygous which states it has 1 tiger gene only.


Like pinstripe royals, a het pinstripe is visuall pinstripe but only has the one gene, the homozygous looks the same but has the two genes

[knotism037]

The above is right as fair as I'm aware.

[Big Jamie]

Originally Posted by quadrapop

when they say het tiger, it means it is a tiger but they are being specific with the word heterozygous which states it has 1 tiger gene only.


Like pinstripe royals, a het pinstripe is visuall pinstripe but only has the one gene, the homozygous looks the same but has the two genes

Cool thanks,
Are pastels the same? a royal het for pastel is a pastel and a super pastel is homozygous for it?

[quadrapop]

yes but some who are trying their luck will try selling normals het pastel because they dont have a clue.

[paulh]

Originally Posted by Big Jamie

As above, can you have a snake het for a co-dominant gene?
For example, tiger retics are heterozygous for the tiger gene and a supertiger is the homozygous form, am I right?
I didn't think you could get a normal het tiger as I've never seen anyone with one and if you bred a tiger to a normal you'd get normals and tigers right?

You are right. 100% correct on the tiger reticulated python.

Another example with a codominant mutant gene: the lesser platinum royal python has a lesser platinum mutant gene paired with a normal gene. This is the heterozygous type. The homozygous lesser platinum royal python has a gene pair with two lesser platinum mutant genes and is a blue-eyed white snake.

My favorite example of a dominant mutant gene is in pigeons If you go out in the park and see a solid black pigeon, that is a good example of a dominant mutant gene named spread. A black pigeon with a spread gene paired with a normal gene is heterozygous. A black pigeon with a pair of spread genes is homozygous. But you'd have to do a breeding test to determine whether a given black pigeon is heterozygous spread or homozygous spread.

With a codominant mutant gene, you can tell the difference between the heterozygous phenotype and the homozygous mutant phenotype.

With a dominant mutant gene, you cannot tell the difference between the heterozygous phenotype and the homozygous mutant phenotype.

With a recessive mutant gene, you cannot tell the difference between the heterozygous phenotype and the homozygous normal phenotype.

[Big Jamie]

Originally Posted by paulh

You are right. 100% correct on the tiger reticulated python.

Another example with a codominant mutant gene: the lesser platinum royal python has a lesser platinum mutant gene paired with a normal gene. This is the heterozygous type. The homozygous lesser platinum royal python has a gene pair with two lesser platinum mutant genes and is a blue-eyed white snake.

My favorite example of a dominant mutant gene is in pigeons If you go out in the park and see a solid black pigeon, that is a good example of a dominant mutant gene named spread. A black pigeon with a spread gene paired with a normal gene is heterozygous. A black pigeon with a pair of spread genes is homozygous. But you'd have to do a breeding test to determine whether a given black pigeon is heterozygous spread or homozygous spread.

With a codominant mutant gene, you can tell the difference between the heterozygous phenotype and the homozygous mutant phenotype.

With a dominant mutant gene, you cannot tell the difference between the heterozygous phenotype and the homozygous mutant phenotype.

With a recessive mutant gene, you cannot tell the difference between the heterozygous phenotype and the homozygous normal phenotype.

Wow! thanks for such a detailed response
I understand the genes completely now in snakes. I'm confused slightly with the pigeons though lol, I think I get it but would blood tests need to be done because a pigeon that is het spread and homo spread look the same, so you can't tell by looking?

Also, what does phenotype mean?

[paulh]

Genotype is the actual identity of the genes.
Phenotype is the effect produced by the genes. In other words, phenotype is what you see, such as albino or super tiger (in reticulated pythons).

In pigeons, normal coloration is slate gray with two black bars on each wing. Spread is a dominant mutant gene that changes the pigeon's normal color to solid black.

Blood tests are not required to determine whether an animal that shows the effect of a dominant mutant gene is homozygous or heterozygous for the gene. All that is needed is to breed it to a normal. If any normal babies are produced, then the mutant individual is heterozygous. If 7 or more babies are produced and none are normal, then there is a 99% probability that the mutant animal is homozygous for the mutant gene.

In the same way, a normal-looking royal python can be tested to see if it is a homozygous normal or heterozygous albino. It is mated to an albino royal python (with a pair of albino genes). If any albino babies are produced, then the normal-looking individual is heterozygous albino. If 7 or more babies are produced and none are albino, then there is a 99% probability that the normal-looking animal is homozygous for the normal gene.

Dominant is simply the mirror image of recessive.

[Big Jamie]

Thanks dude! Cleared everything up completely... those mental pigens...

[paulh]

The Corn Calculator - Corn snake genetics prediction has good definitions of genetics terms and a more detailed discussion of dominant, recessive and codominant mutants.