is there a lethal gene?

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Originally Posted by Anaconda6769

Can you tell me more about this spider problem? I was considering getting a spider tobreed with my pastel,now I am a little nervous about it!!:(

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its nothing to scare you away from spiders but they have a head wobble that most times is pretty minor.

http://ball-pythons.net/forums/showt...ghlight=wobble

I am new to breeding this year,have a pastel/normal pair and was thinking next year a spider or cinnamon with my pastel male!

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Originally Posted by Anaconda6769

Can you tell me more about this spider problem? I was considering getting a spider tobreed with my pastel,now I am a little nervous about it!!:(

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A homozygous lethal mutation isn't necessarily a problem when you only work with heterozygous animals.

As far as I know, womas (the heterozygous version of that mutation) do just fine and make nice combos. I don't actually have any womas of my own but haven't heard of them being problem animals. It's the homozygous version (pearl) that you want to avoid making but that's easy enough; just don't breed two womas together.

It does turn out that spiders (most and maybe all are heterozygous for the spider mutation) have this tendency to flip their heads upside down but they can still be great feeders and breeders so it doesn't seem to bother most of them much at all. Breeding a spider to a pastel you have no chance of making a homozygous spider so even if spider does turn out to be a homozygous lethal mutation it doesn't mater in that breeding. The rumors of surviving homozygous spiders might even be true but if so you have to wonder why the owner(s) haven't gone public with their proven homozygous spiders. I strongly suspect that spider is homozygous lethal but it’s really hard to prove something by it’s absence so we might never know for sure.

Pearl is known to be the homozygous lethal form of the hidden-gene "woma" mutation. (At least according to this thread, it is not yet known if the homozygous regular woma has the same problem.) AFAIK, these animals are born but fail to thrive and die shortly after hatching. (I believe I recall being told that they are extra super loopy, with wicked neurological problems.)

For this reason, I would never want to breed HG woma x HG woma for ethical issues -- not wanting to produce an animal that I knew was going to die. (Of course, this is assuming I could get my hands on two HG womas ... :P)

However, I have never once heard of any sickly, dying snakes coming out of spider x spider or pinstripe x pinstripe clutches. I know breeders often keep secrets, but these morphs have been around awhile now, and plus, the lethal pearl isn't a secret anymore ...

This suggests to me that either A., spider and pinstripe are both dominant (which sounds like a possibility for pinstripe, but I tend to doubt it for spider) or B., the embryos are dying before hatching.

In chinchillas, the option in both homozygous lethal mutations (mosaic, and another mutation called TOV) is B.. There are no sickly homozygous mosaic or TOV babies; they just aren't born.

I do know people who have bred mosaic x mosaic without problems. However, I would never ever risk it. Why? Because in a mammal, if the baby dies before term, it gets resorbed, and can form "mummies" and block up the female's reproductive tract. Thus, when breeding mosaic x mosaic, not only is there a 25% chance that each baby will die pre-term (which is an especially big deal in an animal that gives birth to only 1-2 kits), but you run the risk of serious birth complications for your dam, as well.

In snakes, I dunno if I'd be as worried about that. Snakes pass slugs just as easily as they pass regular eggs, maybe even easier. So while you would, most likely, get 25% fewer viable babies in that clutch, the dead ones likely wouldn't hurt your dam.

So, unlike with chins, where mosaic x mosaic or TOV x TOV pairings should ALWAYS be avoided, I don't really know if there's any real reason to avoid spider x spider or pin x pin pairings ... Except that you may get 25% fewer viable babies. Your theoretical breakdown would be 25% normals, 50% spiders, 25% unborn.

Of course, even if these genes were true dominant, and not homozygous lethal, and there WAS a homozygous spider or homozygous pinstripe ... As a breeder, I don't know if I'd want to produce those anyway. Why? Because there's no way to tell the difference between the heterozygous spiders and the more valuable homozygous spiders. They'd all be, basically, "possible het normal."

So, your spider x spider clutch would be, in theory, 25% normal, 75% "possible homozygous spiders" ... And they'd all just look like normal spiders.

Whereas pairing a spider with the cheapest morph around, the pastel, has a theoretical yield of 25% normals, 25% spiders, 25% pastels and 25% bumblebees -- coming down in price, but still more valuable than a spider alone, still a DANG hot looking snake and integral to some really kickass triple combo morphs.

So, while I'm not really sure what I'll be pairing my spider gal with when she's ready ... It wont be another spider, regardless of the true nature of the homozygous spider form.

WOW:O I just wanna say great thread I am learning alot:gj:

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Originally Posted by Dr_Gonz0

Though it has been made with another gene added IIRC. The Lesser Pearl was done by Kevin McCurley no?

Robin

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Do you know that those snakes are still alive? I doubt it. That theory made zero sense. There is no reason genetically that a lesser or any other morph would make the pearls survive. It looks to be a doomed project though I would like to see someone try a pairing of one of nerds womas to one of the other lines.

Interesting read
http://www.owalreptiles.com/issues.php

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Originally Posted by andyroof1979

Interesting read
http://www.owalreptiles.com/issues.php

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The last post in this thread, before yours, was in August 2009 - almost 5.5 years ago. The thread was actually started in October 2008. Just sayin'... ;)

Lol...I thought it was '13. Nevertheless i am snowed in and bored so was doing some reading and came across the link i posted, as well as this thread and shared my find.

I am also now very confused. If a spider and pinstripe combo is lethal then how do you get a spinner blast. I was told that a spider bred to a pin stripe is a spinner, then the spinner to a pastel will give you a spinner blast, which is what i have. am i correct or is the breeding sequence wrong. I am new to snake genetics.