Reptile & Amphibian Forums

I am of the opinion(through my limited experience)that there are no proven CO-DOM GENES(not traits like pattern)in colubrids like there are in say boas and pythons.My colleague disagrees,siding with anecdotal evidence within his/her own colony.I have HEARD of some before(the HYPO RED MILKS for example)but I have yet to see any proof.IS there any proof out there to be seen? Jeff

I would say that Aztec *MAY* be an example of this, but how does one really prove anything? In my limited experience, corn's tendancies to break the rules is the very factor that contributes to all the morphs we do have. I have seen some striping come up in animals that do not carry the existing "stripe gene", this trait almost seems to be co-dominant, but I have not been working with them long enough to "prove" anything. I am sure there are Co-Dominant genes out there, but we haven't even broken the tip of the iceberg when it comes to fully understanding the existing morphs.
I would almost stick my neck out and say that stripe and motley are co-dominant, but motley seems to be just a little stronger. However, does co-dominant mean that both genes have an equal effect on each other, or does it just mean that they have some sort of effect on each other? LOL... I know it's a crappy answer.

by saying co-dominant do you mean the traits do not mix at all but inherit either one or the other dominantly?

Heretability and morphs are alike but not exact.Jeff

>I am of the opinion(through my limited experience)that there are no proven CO-DOM GENES(not traits like pattern)in colubrids like there are in say boas and pythons.

As far as I know, present concensus is that a mutant gene causes the corn snake's motley pattern. I'd be interested in any information to the contrary.

Are you interested in dominant mutant genes or just codominant mutants?

Xanthic in the black rat snake is recessive to the normal allele. Tyrosinase positive albino in the black rat snake is recessive to the normal allele. When a xanthic BRS is mated to a tyrosinase positive albino BRS, the babies are more or less intermediate between a xanthic and a tyrosinase positive albino. That would seem to be a codominant relationship. See Bern Bechtel's paper in the Journal of Heredity, sometime in 1985.

Richard Zweifel had a paper in the Journal of Heredity sometime in 1982, if I remember correctly. He showed that striped in California king snakes was dominant to normal (banded), though the heterozygote is pretty variable. And striped in San Diego gopher snakes seems to be either dominant or codominant to normal pattern. I think Bechtel was the author of the paper, but I'd have to look up the citation.

I would certainly agree that MOST mutant genes in colubrids are recessives. But more dominants and codominants will probably turn up in the future.

Paul Hollander