Sorry Will, I think he is right (long)

[ Follow Ups ] [ Post Followup ] [ The Ball Python Forum ]

Posted by Randy Remington on May 08, 2003 at 18:10:33:

In Reply to: Will... posted by justsnakes on May 08, 2003 at 16:40:37:

Banana may well turn out to be co-dominant but I don't think you know for sure yet.

It looked like you got some normals and some that I'm hoping grow up to look just like mom. That would be consistent with her having a single copy of a "banana" gene which she passed on to about half of her offspring. If one of her banana babies is male and you breed it to her and produce a different looking "super banana" you could then be pretty sure that it's co-dominant. Technically you should breed the super banana to normals and produce a large number of only bananas to be sure it's homozygous for the banana gene and not just normal variation of what a het banana looks like.

However, it might turn out that the homozygous banana with two copies of the gene looks just like the original heterozygous banana and then it would be considered a completely dominant mutation. There would still be breeding value to super bananas over plain bananas in that they would produce all bananas rather than half. In fact this would be the only way to know you have produced a homozygous animal for a completely dominant mutation. It will be interesting if a spider from a spider X spider breeding will be found that produces only spiders. This will prove that spider is completely dominant and not a co-dominant that no one has been lucky enough to hit yet.

There is another possibility that I hope we don't run into with ball pythons any time soon. We might find a gene that is lethal when homozygous. If you spend a long time breeding suspected co-dominant mutants together but never produce a super you might start to suspect this. It will be hard to prove but it has been seen in other animals. In Syrian Hamsters the "dominant spot" gene is lethal when homozygous. Breeders noticed that dominant spot X dominant spot breedings only produced about 3/4 sized litters and no one ever produced a homozygous dominant spot. They deduced that the 1/4 of the babies that where conceived homozygous dominant spot died in the womb. For this reason they now avoid breeding dominant spot hamsters together because you only get half of a normal sized litter of dominant spot babies whether you breed two dominant spots together or if you breed dominant spot to normal and with the to normal breeding at least you get twice as many normal babies. I suppose technically you could say that �dominant spot� is a co-dominant gene because it has a different effect when homozygous than when heterozygous, the effect when homozygous is that the baby is never born.

:To the best of my Knowlage Co-dom produces supers, Dominant animals just make more copies of them selfs... or do I have it backwards???

:Spiders are a Dominant trait, they only produce more spiders. To my knowlage no super spiders have been produced.

:Pastel Jungles are a co-dominant trait, they produce more pastel jungles and when bred together produce super pastel jungles.

:Did the whole clutch hatch out as bananas?

Follow Ups: