Question about Double Het genetics

[Tim I]

So I recently saw a seemingly reputable breeder selling double HET (ivory and albino) sulcata tortoise hatchlings.
I understand the basics of genetics and heterozygous and homozygous genes.
The breeder states that when these hatchlings when bred back together there would be a 1/16 chance of a new visual morph due to them being double het, I know other reptile breeders do this to create new morphs but can’t find much information on it for tortoises.

I saw there where a few posts of someone selling similar hatchlings 10 years ago claiming the same thing. So now I’m just wondering if anyone knows if those hatchlings ever produced anything or if a mix of leucistic and albino didn’t produce anything noticeable given the similarities.

I know tortoise breeding projects are a lot more rare than say a snake because of the time it takes for them to mature, but just wondering if anyone has any insight.

 

[zovick]

So I recently saw a seemingly reputable breeder selling double HET (ivory and albino) sulcata tortoise hatchlings.
I understand the basics of genetics and heterozygous and homozygous genes.
The breeder states that when these hatchlings when bred back together there would be a 1/16 chance of a new visual morph due to them being double het, I know other reptile breeders do this to create new morphs but can’t find much information on it for tortoises.

I saw there where a few posts of someone selling similar hatchlings 10 years ago claiming the same thing. So now I’m just wondering if anyone knows if those hatchlings ever produced anything or if a mix of leucistic and albino didn’t produce anything noticeable given the similarities.

I know tortoise breeding projects are a lot more rare than say a snake because of the time it takes for them to mature, but just wondering if anyone has any insight.

It doesn't sound right to me. Breeding the two different double hets together, you would expect to get 25% ivories and 25% albinos, plus 50% more double hets for both genes.
No new gene would be produced or brought to the surface (other than accidentally) going by what I know of genetics (which is a fair amount as I have bred many species of tortoises, Ball Pythons, show dogs and pure-bred cats).

That being said, inbreeding (brother to sister, father to daughter, grandfather to granddaughter, etc.) of any type of animal can sometimes bring out recessive genes other than what one expects, but that is not predictable by any biostatistical formula of which I am aware.

 

[jaizei]

Since 10 years ago these double hets were $5000 and now they're like $350, seems like nothing special came from it. Also funny that the current ads are using the same 'lottery ticket' idea that theres a 1/16 chance of striking it lucky and getting a new morph.

I'd imagine that even though both genes are recessive to normal, one of the genes might be dominant over the other. So you get animals that are visual for one trait while also being het for the other.

 

[Tim I]

It doesn't sound right to me. Breeding the two different double hets together, you would get a small percentage of ivories and/or albinos, more hets for the same two genes, plus more possible hets for both genes. No new gene would be produced or brought to the surface (other than accidentally) going by what I know of genetics (which is a fair amount as I have bred many species of tortoises, Ball Pythons, show dogs and pure-bred cats).

That being said, inbreeding (brother to sister, father to daughter, grandfather to granddaughter, etc.) of any type of animal can sometimes bring out recessive genes other than what one expects, but that is not predictable by any biostatistical formula of which I am aware.

Thank you for the insight!
Yeah, the sellers ad talked about the different combinations of hatchlings that would be produced and how the 1/16 one that inherits both would become a super form.
I kinda figure if it was possible someone would have done it by now

 

[Tim I]

Since 10 years ago these double hets were $5000 and now they're like $350, seems like nothing special came from it. Also funny that the current ads are using the same 'lottery ticket' idea that theres a 1/16 chance of striking it lucky and getting a new morph.

I'd imagine that even though both genes are recessive to normal, one of the genes might be dominant over the other. So you get animals that are visual for one trait while also being het for the other.

Yeah, it kinda seemed like a “don't miss out on this chance” sort of ad

Although idk if I just suck at searching but it seems like there was a big gap in selling double het hatchlings from 10 years ago till now, so just wondering if maybe something happened to the original double het hatchlings and they never got the chance to reproduce.

But I may also be overthinking it

 

[zovick]

Yeah, it kinda seemed like a “don't miss out on this chance” sort of ad

Although idk if I just suck at searching but it seems like there was a big gap in selling double het hatchlings from 10 years ago till now, so just wondering if maybe something happened to the original double het hatchlings and they never got the chance to reproduce.

But I may also be overthinking it

Maybe the double hets were/are sterile for some unknown reason.

 

[Arizona Sulcata]

Seems I'm finding this thread a year late... I'm assuming I'm the breeder in question since no one else is producing these. There's one other guy who did many years ago who was charging the $5k because he didn't want to sell any. To my understanding those all died so it's not that nothing came about with their genetics, they just simply didn't get taken care of properly and died (from what I'm told). I charged $350 because it's the price I found that the market was willing to pay, simple as that. You have a VERY small handful of people who would understand their complex genetics and know what they were buying so it all boils down to demand.

If you follow any basic Punnett square or genetic morphism examples from other reptiles/species then scientifically 1/16 of their hatchlings will produce a new morph. And also being bred back together you would be able to produce both Ivory and Albino hatchlings in the same clutch at the same 1/16 rate. Those aren't just random numbers or theories pulled out of thin air.

They aren't sterile or not special, there are just none that have grown to adulthood yet. Think about it... If you had adult Ivories and Albinos why breed them together to make Doulbe Hets when you can sell visual Ivories and visual Albinos for more? That's why they aren't around. I did for the long term project and also because I had a visual Albino female with no male to breed her so I figured why not breed her with an Ivory male. I have a male for her now those which is why no more Double Hets will be produced next year.

It's not a gimmick or made up, it's legit.

 

[jaizei]

Seems I'm finding this thread a year late... I'm assuming I'm the breeder in question since no one else is producing these. There's one other guy who did many years ago who was charging the $5k because he didn't want to sell any. To my understanding those all died so it's not that nothing came about with their genetics, they just simply didn't get taken care of properly and died (from what I'm told). I charged $350 because it's the price I found that the market was willing to pay, simple as that. You have a VERY small handful of people who would understand their complex genetics and know what they were buying so it all boils down to demand.

If you follow any basic Punnett square or genetic morphism examples from other reptiles/species then scientifically 1/16 of their hatchlings will produce a new morph. And also being bred back together you would be able to produce both Ivory and Albino hatchlings in the same clutch at the same 1/16 rate. Those aren't just random numbers or theories pulled out of thin air.

They aren't sterile or not special, there are just none that have grown to adulthood yet. Think about it... If you had adult Ivories and Albinos why breed them together to make Doulbe Hets when you can sell visual Ivories and visual Albinos for more? That's why they aren't around. I did for the long term project and also because I had a visual Albino female with no male to breed her so I figured why not breed her with an Ivory male. I have a male for her now those which is why no more Double Hets will be produced next year.

It's not a gimmick or made up, it's legit.

You are using words that imply there is certainty; there is not. There is no guarantee that scientifically 1/16th will be a new morph, ivory or albino. Those numbers are in fact "theories". Over time long term, the rates may roughly equal whats shown on a Punnett square but its by no means predictive.

By crossing ivory and albino hets, without knowing what a visual would look like, theres no way to know if an animal is a "new morph." Maybe that 1/16th animal looks just like one or the other. Theres a reason its considered a faux pas to cross different strains of albino.

 

[Arizona Sulcata]

You are using words that imply there is certainty; there is not. There is no guarantee that scientifically 1/16th will be a new morph, ivory or albino. Those numbers are in fact "theories". Over time long term, the rates may roughly equal whats shown on a Punnett square but its by no means predictive.

By crossing ivory and albino hets, without knowing what a visual would look like, theres no way to know if an animal is a "new morph." Maybe that 1/16th animal looks just like one or the other. Theres a reason its considered a faux pas to cross different strains of albino.

I do agree that there is no certainty because it hasn't been done before with this particular species. But in comparing other species it's safe to predict (not guarantee) it would follow past genetic morphism examples that we have. There's certainly never any guarantees when it's never been done before. We can guarantee however that they would produce both Albinos and Ivories and be the only morph that can do so for both strains.