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Genetically defective?

fyrefocks

fyrefocks

Nate lover
Last year I bred a caramel diffused motley/stripe to her brother, a diffused motley/stripe. A small clutch was produced, of which 5 eggs were fertile. 3 went the distance and hatched. 1 of them had only a small kink just behind the tail. It went on to feed so I gave it away. It died before reaching 6 months old. The other 2 babies that hatched were so badly deformed that I put them down. The other 2 eggs were DIE, and were both badly deformed.

I suppose this could have been a case of inbreeding gone wrong, however, as it turns out, my thermometer was malfunctioning and I actually incubated the clutch at 90. This could obviously also be the cause of the deformities.

Obviously I needed to repeat the pairing. Which I did.

This year I got 13 fertile eggs and they all went the distance. With a new thermometer at the ready, I made sure to incubate them even lower than I normally shoot for. In this case I cooked at 84 and they began pipping on day 56. I got 12 perfectly healthy babies and 1 baby that had a kink in it's neck and it only had 1 eye. This baby didn't survive to the first shed.

It's been almost a month now with these 12 babies and every single one ate on the first offering and every one of them has eaten at least 3 times.

My question is, given the results of years 1 and 2, how do I sell them? Are they genetically off? Should I give them away because of the defects from the one baby this year or last year's babies?

The sire has produced with other females with no problems, so this is either an inbred thing or it's the female's fault. I haven't bred her to anyone else yet, obviously, but I will next year. But in the mean time...?
 
Hard to say for sure, but I would make sure you give all that information to anyone looking to take in one of those babies. They would probably best be labeled as "pet quality" and not used for breeding programs, but I try to avoid inbreeding more than most breeders.
 
cguarino30 said:
Hard to say for sure, but I would make sure you give all that information to anyone looking to take in one of those babies. They would probably best be labeled as "pet quality" and not used for breeding programs, but I try to avoid inbreeding more than most breeders.
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I have no plans to sell pairs, and obviously full disclosure is a must. I guess I really just want to know if I should be giving them all away or if I can actually try to sell them.
 
I think the poor first season was a result of incubating at 90. I think _any_ clutch can have a baby with something wrong. Just like in humans, who aren't related at all. Actually, maybe you should consult our geneticist, Duxor.

Out of curiosity, how did the weights of the hatchlings differ?
 
Nanci said:
I think the poor first season was a result of incubating at 90. I think _any_ clutch can have a baby with something wrong. Just like in humans, who aren't related at all. Actually, maybe you should consult our geneticist, Duxor.

Out of curiosity, how did the weights of the hatchlings differ?
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I didn't even weigh last year's babies. If I had to guess, I'd say the 3 that hatched probably weighed between 6 and 7 grams. This year's babies all came out about even across the board, right around 6 grams.

I'd like to think that the over heating was the issue as well. Still, this situation is a first for me and I'd like to approach it in a manner that would be considered acceptable to the community.
 
I would like to hear what everyone else has to say, but I would have no problems purchasing one, but full disclosure of the previous year's clutch would be nice. You could always do some sort of extended guarantee- not for life, obviously, but some period of time longer than usual.

If the first season hadn't happened, and you only had this year, with the one deformed baby- that can and does happen in any clutch, related or not. Would you still be questioning yourself then?
 
Nanci said:
I would like to hear what everyone else has to say, but I would have no problems purchasing one, but full disclosure of the previous year's clutch would be nice. You could always do some sort of extended guarantee- not for life, obviously, but some period of time longer than usual.

If the first season hadn't happened, and you only had this year, with the one deformed baby- that can and does happen in any clutch, related or not. Would you still be questioning yourself then?
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Yes, but only because the parents are direct siblings. If the parents weren't related at all, I think even with the knowledge of last year, I'd not have a second thought based on this year's outcome. I'd sell them like normal.
 
Using siblings or parent to offspring is said not to cause any problems and has kind of become standard practise since a lot of breeders sell 1.1 pairs of clutchmates. I think the way it works is that putting closely related snakes together doesn't cause a "bad" gene, but if there is already one floating in that gene pool it increases the chances of that trait appearing visually.
Like Nanci I am inclined to suspect the temps over the genetics. 90 will cook anything so I would expect those results. I think your new incubator will fix the problem, but if I had my doubts about a snake I would either rehome it as a pet or at least tell the buyer all the facts and let them decide if the risk is worth it.
 
ghosthousecorns said:
Using siblings or parent to offspring is said not to cause any problems and has kind of become standard practise since a lot of breeders sell 1.1 pairs of clutchmates. I think the way it works is that putting closely related snakes together doesn't cause a "bad" gene, but if there is already one floating in that gene pool it increases the chances of that trait appearing visually.
Like Nanci I am inclined to suspect the temps over the genetics. 90 will cook anything so I would expect those results. I think your new incubator will fix the problem, but if I had my doubts about a snake I would either rehome it as a pet or at least tell the buyer all the facts and let them decide if the risk is worth it.
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If it helps any to know this, I cooked 5 clutches at that temp. 2 clutches hatched prior to the "defective" clutch with absolutely no ill effects, then the "D" clutch (at which point I found the temp issue and turned down the temp), then 2 clutches after (with only half incubation time too high) with no ill effects.
 
3rd time's a charm...

It sucks from an extra caging standpoint, but I'd hold back this season's clutch. Get mom/sister nice and beefy, fully recouped from this season. And then I'd lather, rinse, repeat for 2015.

HOWEVER...
Bump the temps down more, if possible. My herpstat is set at 82.5°F to power my 'bator, with incubation temps running 83.3-84.7°F. The elevation to 84 was recent and I'm trying to understand that since we keep the house in the mid 70s until the wife and I go to bed. If I could afford to cool the house more, I'd love to shoot for an incubation temp of 82-83. I know some formerly prominent breeders that don't even incubate their North American colubrids that warm any more; stick the eggs in a 1 gallon pickle jar with some vermiculite or perlite, cover with sphagnum moss, and they toss them up on a shelf in a warm closet.

I do agree with Nanci. Last year's clutch was an anomaly due to the 90°F incubation temp. I had similar happen back in 2002 with both corns, great plains rats, and some leopard geckos due to moving as a result of mom selling our first house as part of divorce terms. The move caused a massive temp spike in my oh so trustworthy hovabators. All my corns and gp rats that did hatch, hatched in under 60 days (I think around day 52) and all came out kinked. Those that didn't hatch were deformed in egg. The leopard gecko eggs incubating during that temp spike hatched with eyelid and head/body deformities (from pairings that never had issues the prior 5 years).
 
HerpsOfNM said:
3rd time's a charm...

It sucks from an extra caging standpoint, but I'd hold back this season's clutch. Get mom/sister nice and beefy, fully recouped from this season. And then I'd lather, rinse, repeat for 2015.

HOWEVER...
Bump the temps down more, if possible. My herpstat is set at 82.5°F to power my 'bator, with incubation temps running 83.3-84.7°F. The elevation to 84 was recent and I'm trying to understand that since we keep the house in the mid 70s until the wife and I go to bed.

I do agree with Nanci. Last year's clutch was an anomaly due to the 90°F incubation temp. I had similar happen back in 2002 with both corns, great plains rats, and some leopard geckos due to moving as a result of mom selling our first house as part of divorce terms. The move caused a massive temp spike in my oh so trustworthy hovabators. All my corns and gp rats that did hatch, hatched in under 60 days (I think around day 52) and all came out kinked. Those that didn't hatch were deformed in egg. The leopard gecko eggs incubating during that temp spike hatched with eyelid and head/body deformities (from pairings that never had issues the prior 5 years).
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I don't know that a third time with an even lower increase in temp will show me much. Before last year's issues, my always and forever cook temp has been 86. And I've never produced a deformity at that temp.

I think that since the sire has produced with a different female, a pairing that produced no deformed babies, the better idea would be to breed the dam to a different male. If she throws a deformed baby next season with another male then I know she is the issue.

Housing the babies seems a bit excessive. I don't mind Nanci's extended warranty idea, though.
 
But the female's supposed defective gene has to meet up with a defective gene from the male. Man, I read a paper about deformities in closely-related animals, it had to do with isolated populations, about how they were actually less likely to have deformities than the general population. I'll have to look for it at work Monday. I want to say, though, that it was along the lines of defective animals were weeded out by natural selection, leaving only the animals without defects to breed. Because, since the population is closely related, the defective genes have a better chance of combining, so then, as those defective animals are eliminated, the non-defective survivors go on to produce offspring without the defect.
 
Nanci said:
But the female's supposed defective gene has to meet up with a defective gene from the male. Man, I read a paper about deformities in closely-related animals, it had to do with isolated populations, about how they were actually less likely to have deformities than the general population. I'll have to look for it at work Monday. I want to say, though, that it was along the lines of defective animals were weeded out by natural selection, leaving only the animals without defects to breed. Because, since the population is closely related, the defective genes have a better chance of combining, so then, as those defective animals are eliminated, the non-defective survivors go on to produce offspring without the defect.
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So I should just remove the dam from my breeding population altogether?
 
Inbreeding causes defects in humans because we all carry lethal or disadvantageous recessive alleles but are heterozygous for them so are fine. Mating a sibling to a sibling thus increases the odds of the offspring being homozygous for those deleterious alleles.

I think the problem is more severe in mammals. But I would still expect inbreeding in snakes to increase the odds of creating offspring that are homozygous for disadvantageous alleles. However, since snakes seem so sensitive during embryonic development, perhaps those that are homozygous for deleterious mutations usually die in the egg? Offspring that look healthy and feed are presumably those that didn't lose the genetic lottery, although perhaps they might be more prone to health problems down the road.

Basically, genetic diversity=good. But I'd think if that were your problem you wouldn't have expected to hatch 12/13 healthy snakes in this last clutch.
 
Nanci said:
But the female's supposed defective gene has to meet up with a defective gene from the male. Man, I read a paper about deformities in closely-related animals, it had to do with isolated populations, about how they were actually less likely to have deformities than the general population. I'll have to look for it at work Monday. I want to say, though, that it was along the lines of defective animals were weeded out by natural selection, leaving only the animals without defects to breed. Because, since the population is closely related, the defective genes have a better chance of combining, so then, as those defective animals are eliminated, the non-defective survivors go on to produce offspring without the defect.
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Yes, in the lab we inbreed animals generation to generation and eventually we wind up with animals assumed to be homozygous at every locus. Any really bad deleterious alleles would have been weeded out along the way. But it takes many generations.
 
Dux, can you address the difference between deformities that are genetic as opposed to developmental? Would the one-eyed baby be more likely to be one or the other?
 
Also- on a side note- I would LOVE to see someone test breed an above-the-vent kink to a non-related same, and document the results. I am not convinced that kinking is genetic, as opposed to developmental or incubation-induced (if that is different).
 
fyrefocks said:
DuxorW, since I have you here, can you also tell me why Murphy chose to give me no amel based babies when both parents are het amel?
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Same reason Murphy didn't give me any stripe babies in a clutch of 13, parents _proven_ heterozygous stripe. Each egg is a single event, unaffected by the cumulative odds of the others.
 
So right what I'm gathering is that:

a- I can sell the babies, full disclosure of course.
b- I should remove the dam as a breeder. (no one recommended this but I get the feeling it would be a good idea)
 
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