Reptile & Amphibian Forums

It's been a VERY long time since I've last posted here. I hope all the veteran forum members are all doing well.

I have a female corn snake that I kept in my classroom at school that laid about 12-13 bad eggs. Here's the kicker...she had never ever been with a male. In fact, I plan on breeding her in the future but she is too young/too small at the moment. Well... one of the eggs looked almost white in color and I thought it may be viable. I have been incubating it and I'll be darned if it isn't now hatching. I expect this little baby to be an exact clone of the mother.

My question: Has anyone had a parthenogenic corn snake lay viable eggs that hatched successfully? Is it common? I know this happens in some lizard species.

Please comment/share...
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Sincerely, Jason
www.NortheastSnakes.com
NortheastSnakes@verizon.net

Someone else had this happen this year, but the egg didn't go to term.
Well, sir, if there is no possible other explanation (NEVER been with a male), then it must be possible.

If it is any variant from mom pheneotypically, the female must have been with a male at some point.

let's see both mom and baby!
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Jack Jeansonne

That's not accurate. In snakes the sex chromosomes are designated ZW and it's the females that have the two different sex chromosomes, not the males. The only sex chromosome combinations that are viable is ZW and ZZ. The other possibility, WW, is inviable and the organism will not develop. In cases of parthenogenesis, the eggs have gone through meiosis, which halves the chromosome number. The end result is that the embryo ends up with duplicates of each chromosome, which means the offspring can only be ZZ or WW (inviable).

The offspring of such an event will not be clones of their mother. For one, it'll be male. For another, any traits that the parent was heterozygous for, the offspring will be homozygous for one of the alleles.

Well...the baby only had enough energy to make one slit with it's egg tooth....after a 24 hours and no sign of it exiting the egg, I cut a little window and the baby was dead inside the egg.
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Sincerely, Jason
www.NortheastSnakes.com
NortheastSnakes@verizon.net

Parthenogenesis is a well-documented, though poorly understood, phenomenon in both lizards and reptiles. This is the first I am aware of it occuring in a corn snake. All the species I know have been documented with parthenogenesis have been either desert or island species, where (conceivably) finding a mate isn't always that easy. It is highly probable that parthenogenesis is controlled by different mechanisms in different species, though the apparent outcome (virgin birth) is the same. I am not aware that anyone has taken the time to do DNA analysis on mother and babies. Though it is likely that the offspring are clones (perhaps the result of a germ cell that has not undergone meitotic division), the offspring could also be the result of selfing where two germ cells somehow merge. Selfing is well documented in plants, and results in genetic variation even though there is only one parent plant. Regardless of whether the offspring is a result of cloning or selfing, the offspring does not have to phenotypically look like its parent. I know of at least one cloned cat that was a gray and white tabby while its "mother" was a calico. DNA is just a blueprint, and that blueprint still has to interact with environment, which may lead to an organism that differs from the "ideal" of the DNA blueprint.
Of course, I'm just shooting from the hip here with the little I know while trying to get the kids breakfast. If someone knows more about parthenogenesis, please share, especially with some links or book recommendations...

Zach