Exciting findings on Paradox inheritance!

We are very excited to announce and reveal the results of the line breeding we did this year. The results are jaw dropping to say the least, and was not exactly what was expected.

Our female Hypo Granite has been consistent in producing Paradox offspring. She produces them regardless of the male used. We decided to see what would happen if she was bred to a Paradox of her own familial line.

Enigma, the offspring Hypo Granite Paradox DH Albino Green from 2016 fathered this clutch and the results speak for themselves.

There is an increased number of minor Paradoxed animals. And then there is this animal: a Black Eyed Ivory/ Albino Granite Paradox Female.

On the genetic standpoint: we know that the dam does NOT carry Albino. We also know that this is not a case of androgenesis (the equivalent of male parthogenesis) as the animal would have to be male. As this is not the case, and the animal is female, it’s showing promise that this is a case of paradominant inheritance of mosaicism.

Paradominance is described as such: animals that carry the paradominant gene appear normal, and the gene may go through several generations without ever expressing. The Paradox mutation only occurs when a postzygotic mutation occurs in the egg during early development. This mutation causes a lack of heterozygosity, meaning some of the alleles are turned off on parts of the skin, showing only homozygous or hemizygous genes in random splotches.

While this is a working theory that fits this case of familial line of inheritance, it’s still just a working theory on why Paradox, which used to be considered sporadic and random, has been linked to being partially replicatable in family lines.

We at Cold-Hearted Exotics will be working with these family lines to prove further the mode of inheritance for the Paradox mutation. Because of our lines showing a type of inheritance, we will be calling the animals “Enigma line” as we cannot prove the full genetics yet. Because the mode of inheritance is familial, there is a chance that each offspring could pass the mutation, even if they appear normal. This is not a guarantee, as paradominance can hide for several generations.

We hope you enjoy learning about this phenomenon with us. We will continue provide healthy, quality animals while trying to progress on this trait through test breeding and other means of gaining further knowledge on the topic.


That is pretty cool. How many paradox offspring does she produce in a clutch? How much of an increase did you see when you bred back to her? Also, what kinds of paradoxing are you seeing, is it just what is pictured or are there other types of paradox that show up?

There was a definite increase in Paradox animals. Here are previous breedings.

2016: just Enigma (and a blip on another, didn’t call it a Paradox) sire: Albino Green Granite
2017: one hypo granite male, and heterochromia Ivory. Sire: Hypo TH AGG
2018: 2 hypo Granite, one mild blip. Sire: Albino Green Granite
2018: Ivory/Albino Granite, 3-4 Hypo Granite with some spots or blips. Sire: Enigma

There’s also some irregular marked Granites. Usually voids on Granite markings occur in the first 1/3 of the animal, whereas some of these are last 1/3 voids with full pattern in the first 1/3 instead. Basically reversed.

You have made a small mistake in your analysis here. Like parthenogenesis, animals produced from androgenesis are only females because in both scenarios you have a doubling of the sex chromosomes. In partho, since the females only have X chromosomes, the only possible outcome is XX or female. In andro, because males are XY, you have the possibility of generating either XX or YY combinations but the YY genotype is non-viable so, again, the only possible outcome is XX or female.


Incorrect, the two chromosome given by androgenesis would be both XY, because it’s the only chromosomes available. It’s why is species that have heavy androgenesis numbers, they have lots of female function or loss of female population, and thus population extinction occurs because the population is forced to be male only by androgenesis.

The male donates all it’s chromosomes when androgenesis occurs. If the donation occurs because there is no nucleus in the female’s egg, all the genetic data including sex chromosomes are used. If the donation occurs due to androgenetic hijacking of the egg, it still remains that all the male’s data is used. This includes both sex chromosomes; not one choromosone duplicated.

Citation: The American Naturalist, Vol. 161. No. 4. ‘The Evolution of Androgenesis’ written by Mark.J. McKone and Stacey L. Halpern

Either way, the mosaicism of Paradox reptiles most closely resembles the mosaicism expressed in other animals which is via a suggested paradominance.

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As a geneticist working extensively with both parthenogenesis and androgenesis in snakes, I can tell you that androgenic boas and pythons can be female. Given that boas and pythons have XX/XY sex chromosomes, we know XX is viable (as we have female androgens). We do not know if YY males are viable yet.



One more thing, we hve no evidenxe that androgenic males contribute both X and Y chromosomes at the same time. We have genomic data for androgens already collected and all are genetically depauperare showing bear genome-wide homozugosity. This would be possible with both X and Y chromosomes as the same would have to happen at all chromosome pairs.


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Do you then think that this is solely a case of androgenesis, which is quite rare, seconded with a mosaicism?

Do you agree that the studies of paradominance being the source of familial mosaicism is accurate?

I cannot address the genetic basis of mosaic animals. We are collecting samples for sequencing, but we need dead animals to sample multiple tissues.

But, just like parthenogenesis, in boas and pythons, androgenesis is not rare at all.


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I would love to read any studies or literature on this, as every other article and writing had dictated androgenesis as rare in most vertebrates, minus several species of fish, but very common in inverts like ants, clams, and plants. I know parthogenesis is the most common form of asexual reproduction in reptiles, but have yet to find any concrete evidence of androgenesis besides one case of a incomplete dominant heterzygous gened male breeding a normal female and producing 3 homozygous males.

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There are plenty of papers on parthenogenesis in snakes on my lab page - www.booth-lab.org. We have not published our newest work on androgenesis or the genomic architecture of parthenogens yet.



Which is probably why I haven’t found further research. I will look forward to seeing it when it’s published.

In the case of this female, do you think it’s androgenesis or mosaicism?

All speculation until genetic screening is done.


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How would genetic screening be done?

Excellent thread. Hope the discussion continues.

Try contacting Rare Genetics

I’m still in the learning phase of how paradoxes are possible, so I would like to thank everyone for contributing to this thread. It has help me understand a little bit more about these lovely crazy little snakes.
The pictures I attached are two that I have hatched out this season. The clutch was 6 eggs total and all very unique, but these two are still a mystery to me. The female was a Pastel Champagne x Black Pastel and a Banana. Once again thank you all for the contributions to this amazing hobby.

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My question I have is, Is there any draw back with reptiles that have the paradox? Neurological, kinks, eating issues, or shortened lifespan? Has anyone experienced a link to paradox and any of these issues or others not mentioned?

I have spoken with a number of people with paradox animals and none of them have reported issues.

The one thing that can come in to play is when you breed them - depending on how the mosaicism/chimerism is distributed within the body the sex organs can be effected. This can be something simple, like an animal breeding out like a het rather than a visual or as a WT rather than a het, or it can also be something extreme, like having an animal that pops hemi-penes but has ovaries instead of testes. The prior has been directly documented in paradox carpet pythons by two separate breeders (Nick Mutton and Wayne Larks)

I have not had an increase or decrease in defects in relation to the Paradox mutation