Tail kink genetic mutation due to backcrossing??

Hi

I wanted to ask the breeders that post here if the tail kinking that I am seeing on some of the new morphs being sold might be genetic. I have seen it mostly in some patternless albinos being sold, and some rainwater albinos.

Any ideas? I read somewhere online that this is the case, but now I am unable to find the source again.

Thanks!

Terry

Although I don't think there is any real scientific data, based on my professional experience I believe it is a genetic trait... especially in patternless leopard geckos. I have seen it primarily in males, and occasionally the tail will 'un-kink' as the baby grows, and I have seen instances when they will develop a tail kink as they mature.

There are exceptions where it may be congenital. For example, I had a SHT come out of the egg with it's tail bent completely in half.. apparently from it growing improperly in the egg.

Personally, I feel that this trait should be culled from the species, and leos that display this defect should not be bred. It would only take a few years to eliminate this undesireable trait if all people breeding geckos would simply do this. Of course, these little kinked tail geckos still deserve a good, loving home and make wonderful pets!

Thanks Marcia!

By the way, I like your web site and the policy you have for ensuring genetic diversity within the Leopard Gecko species.

Regards,

Terry

Some species and mutations seem much more prone to brith defects than others. albino burmese pythons are notorious for kinks in the tails and spines as well as large eyes, small eyes, one eye and other defects. Origional strain albino colombian boas also are notorious for eye defects and babies with no eyes. Other species that are inbred even more heavily do not have as many problems, like cornsnake mutations. It is definitely genetic but seems to vary from species to species. It is also a factor to consider with birth defects if the temperature during incubation fluctuated or is too high. You will get kinks and other problems there too. Evan

I agree with Marcia that a lot of the kinked tails, especially in the patternless, are a genetic trait that can be passed down. It was very prevelent in patternless for years, and in fact, in the late 1990's it was difficult to find a patternless leopard gecko without a kinked tail. Of course there are cases where tail kinks are probably caused by incubation issues such as temperature fluctuations, too much humidity etc. as well. A breeder should be very careful not to breed any kinkies that he or she feels are genetic, they should be removed from any breeding program and sold as pet only IMO.

Couple important things to remember...

Inbreeding can't create genetic problems, it merely strengthens existing genetic traits.

Simple recessive genes are actually the easy ones to understand... there are other genetic traits which are quantitative. The outcome in any given pairing is somewhat unpredictible but certain traits become stronger as they are reintroduced. Everyone knows how this applies to positive traits, if you want really yellow leopard geckos you find the two brightest yellow animals you can find and breed them... then breed the brightest offspring, then breed the brightest offspring, then breed the brightest offspring, then... And so on. This can be applied to negative traits as well.

Many morphs are the result of a recessive trait. Since the recessive trait is most easily replicated by crossing animals known to share the trait, line breeding is common. IF an individual used in the initial breeding project (to prove out the trait or begin commercial production) has a genetic tendency of any kind, that tendency will eventually come to the surface, even if hidden. Most of these clearly genetic tendencies towards negative deformities were likely introduced early on, via a carrier animal which displayed no outward signs of the problems. The earlier in the program it was introduced, the more widespread the problem is.

A breeder should be very careful not to breed any kinkies that he or she feels are genetic, they should be removed from any breeding program and sold as pet only IMO

Is a sentiment I fully agree with, although I take it a step further. Nobody can guarantee beyond a shadow of a doubt that any animal they produce will never be used in a breeding project unless they have it sterilized (not gonna happen, herp surgery is expensive enough as it is). Humane euthanization is a very valuable tool when it comes to keeping not only your own projects, but the general captive population safe from genetic defects. Culling any offspring which display a negative trait which can't be verified to be formative or due to injury is good for the animals and good for the hobby... If you have adult breeders which regularly throw offspring showing a deformity, they should also be removed from the breeding population. If you have siblings of deformed individuals, same scenario... Any clutchmates of a deformed individual are carrying the same genes which caused the problems for the kinked animals.

Seamus-

In theory you are correct, but I am a softee and I just cannot put down a leopard gecko that is perfectly healthy but has a kinked tail. Now, if they hatch out with no eyelids or something like that that is going to hamper their existance then yes. But kinked tails, no way, I just can't do it!

I am a softee and I just cannot put down a leopard gecko that is perfectly healthy but has a kinked tail. Now, if they hatch out with no eyelids or something like that that is going to hamper their existance then yes. But kinked tails, no way, I just can't do it!

A common attitude and not a bad thing in and of itself.

The fact that you can't indicates that you genuinely care for the animals you produce, there's an emotional attachment of a sort to each and every animal you own... I don't think you're one of those "my equanna luvs me" types, but YOU can care for the ANIMALS. This means they get better care and treatment, more individual attention to detail and you're quicker to notice and respond to any problems which may come up (but they're overall less likely due to higher quality care to begin with).

You're also a responsible individual though and would never use a kinked individual in a breeding program (genetic or formative kink, healed injuries are a whole different ballgame). For those not willing to devote the time or expense to maintaining animals solely as pets, HUMANE euthanization is the appropriate option.

It's not something a lot of gecko people might want to consider but... I've found that kinked or deformed animals are very useful as feeders for other animals inclined towards consuming herps. A deformed leopard gecko might be just the thing that greyband needs to jumpstart it's digestive system and put it on the route towards eating scented pinks. I've often wondered if there isn't a resale market for deformed animals at a drastically reduced price if such a market were to be approached. Please understand that I'm not saying this for shock value or to be cruel... it's simply a useful outlet when unfortunate circumstances rear their ugly head. A means of keeping deformed individuals out of the breeding population in a definite manner (There really is no telling what anyone else might do with a kinked animal, they may promise to keep it as a pet and never breed it and then change their stance).

Thank you Seamus, and I agree with you on this too:

It's not something a lot of gecko people might want to consider but... I've found that kinked or deformed animals are very useful as feeders for other animals inclined towards consuming herps. A deformed leopard gecko might be just the thing that greyband needs to jumpstart it's digestive system and put it on the route towards eating scented pinks. I've often wondered if there isn't a resale market for deformed animals at a drastically reduced price if such a market were to be approached. Please understand that I'm not saying this for shock value or to be cruel... it's simply a useful outlet when unfortunate circumstances rear their ugly head. A means of keeping deformed individuals out of the breeding population in a definite manner (There really is no telling what anyone else might do with a kinked animal, they may promise to keep it as a pet and never breed it and then change their stance).

Oh, BTW, alterna don't seem to like them very much.

Oh, BTW, alterna don't seem to like them very much

Yeah, that's true too, they usually seem to want to hold out for Coleonyx. Asian vines seem to take leos fairly well though... I've had good success using them for stubborn aspera too. Then there's an entire range of monitors to which parasite free and inexpensive lizards are much better for nutritionally than rodents are.

General point being though... if they are going to be euthainized, they may as well have some use. If a breeder doing the responsible thing in removing them from the gene pool can make a couple bucks selling them as feeders, then more power to them.