Quote Originally Posted by sungmina View Post
It was not about how much the spider was possibly more heavily inbred than other morphs (although I will ask about this again and get back to the OP) it was about the possibility that the spider (pattern) gene and the wobble gene sit right next to each other on a chromosome. The thought is that early inbreeding caused the issue and then since the issue sits so close to the gene we are trying to cultivate, it is near impossible to separate.

Therefore in breeding the spider, although there may be far more outcrossing now than any other morph, it is unlikely to 'get lucky' and have a split between the two genes. If the pattern and wobble sat far apart on the chromosome, a split could occur anywhere in between and separate the two. However if they sit right next to each other, despite all the outcrossing, the split would have to occur at the single spot between the two, which of course would be very rare, but not impossible.

I want to note that this is all speculation about the genetics of the wobble, nothing is definite. I am not saying that there are 100% for certain spiders without wobble, I'm just saying I believe the possibility exists.

I tend to agree with Robin that the spider gene and spider "wobble" are most likely plieotropic effects of the same gene -- ie, one mutation causing both the difference in pattern and the neuro problems.

That having been said, I absolutely concede that linkage (two separate genes that are very close on the chromosome) is possible. However, inbreeding would have had nothing to do with this. As Robin said, the first spider out of the wild was "loopy;" any initial inbreeding wouldn't have "fixed" the linkage any more than a whole bunch of initial outcrossing would've done.

To me, it's almost meaningless whether it's one gene or two linked ones, because the practical upshot is the same: The spider and wobble are going to be very difficult, if not impossible to separate. In goats, the gene for being polled (no horns), a desirable, dominant trait, is very tightly linked to a gene for being a hermaphrodite (an undesirable, recessive trait). We know this for a fact and yet still can't separate that bad hermaphrodite gene from the good polled gene despite years of breeding.

Now, I do think that there may be other genes that can modify and "tone down" or "tone up" the effects of the neuro gene ... But I don't think you can ever fully breed it out.

As far as the homozygous spider goes, to me it's almost (almost!) a moot point. I think one thing we can be fairly certain of is that there's no visually distinct homozygous spider (unless Sungmina's friend wants to come forward with his). Therefore, it's going to be impossible to differentiate a homozygous from a heterozygous spider. Therefore, you won't be able to tell your more valuable homozygous animals from your less valuable heterozygous ones. I wouldn't breed pinstripe x pinstripe for the same reason ... I guess the only real reason it might make a difference (to me) is that if I ever REALLY wanted to breed a male that carried the spider gene to a female that did as well, I might want to know if I was likely to get 25% less babies, or if I should plan to market the spiders as "33% possible homozygous." That, and for pure, geeky, gee-whiz curiosity.