Reptile & Amphibian Forums

I have a few questions and will post them separately. My first question is more of a clarification to what appears to be a misunderstanding on my part. I was told this week that if I bred a super pastel to say a spider or other single codom animal that only one of the pastel genes would pass on to the offspring. In other words I can't produce killerbees from that pairing when I thought you could.

you cant produce a super pastel unless you have pastel in both the male and female you are breeding.
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Evan Stahl Reptiles
www.evanstahl.com

That's what I was told and was afraid of having confirmed here. My planned projects are now screwed due to this misunderstanding. I don't get why a double codom animal can pass along both traits and yet a super can't. It's 2 pastel genes or cinnamon genes, etc. It is what it is, but not what I had hoped to hear. Thank you Evan for replying.

The reason is due to the location of the two codom traits. In a super the two copies are located directly opposite each other so when the DNA helix splits to form sperm or egg only one of the two gets passed. In a double the traits are located far enough apart (i.e. different chromosomes) to allow one or the other or both to be passed to a single baby.

Hope that helps,
John

you wrote ,,,far enough apart so that one- or the other -or both can be passed on.....(both)

meaning the super pastel x spider could produce killerbees...as well as super pastels...

even I have a brain freeze on this one right at the momment...

I gotta wake up more...>>>...
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........JY

No, I was refering to a double co-dom animal such as a bumble bee or a lemon blast, as opposed to a super. A super pastel x spider would be a super to a single and would fall under the first example I gave.
I was trying to point out that when two traits are located on different chromosomes they can be passed independently (and without regard to which parent they came from). For example, a bee can pass spider, pastel or BOTH but a super pastel can only pass 1 copy of the pastel gene.

This is one reason why I disagree with those who want to call a super a "double" codom or a killer bee a "triple"

Sorry if I wasn't clear.
John

Thank you John. That is a good explanation as to why it happens that way. Too bad that it works that way though I will need to rethink my upcoming crosses.

Good thing with supers is that you sure that all the offspring will be at least pastel.

Breeding a super pastel to a normal, will produce all pastels.

Breeding a Pewter (Pastel x Cinnamon) can produce Pewter, Pastel, Cinnamon and Normals.

Actually, being sure that you don't produce normals anymore is a good thing.

Breed a Super Mojave to a Super Pastel, and you will produce all and only Pastave.
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love this world, don't hate it.

To expand this a bit more (genetics 101), all organism above bacteria have chromosomes that com in pairs, you get on chromosome form your father and one from your mother.

In the case of a trait like Pastel, that is found in a single strecth of DNA on the same chromosome at the same spot in every snake chromosome. Therefore, when you get a pastel gene from the mother and father, you end up with a super pastel because it has 2 copies of the pastel gene, one on each of its chromosomes.

Now, when the cells go through meiosis to make sperm/eggs, the chromosomes divide so that each sperm/egg gets only a single chromosome so it can carry only a single pastel gene and pass on to a baby a single copy. Barring some cancer type duplication, a sperm/egg can get only a single copy of the pastel gene.

In the case of a double/triple codom, the genes that carry the pastel trait and the spider trait are different genes that are carried at different places on the chromosomes. This means that as the pairs of chromosomes divide, the sperm/egg can get either none of the pastel and spider genes, only the pastel, only the spider, or both the spider and the pastel (bee).

Other things come in to play when you get more complicated like the superstripe.

Well explained !

Hopes everyone understand !
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love this world, don't hate it.