I did a write up on the spider, double check it for me?

[blackcrystal22]

as far as no homozygous form existing.... It is a gene that affects an allele with locusts..... just like everything else.... To think that there is no way for an animal to inherit a gene from both parents is ridiculous...... I dont know if the homozygous form is lethal, I personally dont think any of us do... The woma gene is homozygous lethal we see the offspring fail to thrive.... There are a million threads on homozygous lethal spider and the only conclusion we ever seem to come up with is simply we dont know.... As far as recessive lethal we would not see the spider pattern show in a heterozygous animal if the gene was recessive.

You obviously don't understand a word I said. The gene is recessive for lethality, but dominant in nature when the animal lives.

Recessive means that the trait needs both alleles to exist. In this case, the trait of lethality is recessive because it only happens with both alleles. The spider coloration itself is not recessive, but is associated with the lethality when both alleles are present.

For example, the normal gene becomes a recessive gene when paired with the spider gene because the spider gene acts dominant. Genes can change from dominant to recessive in the presence of other dominant genes.

The day you can breed and prove a homozygous spider, you will disprove the idea of recessive lethality for that gene. Pinstripes were also thought to be like this but Brian at BHB claims to have a homozygous pinstripe, so we'll have to wait and see if that proves out. (You really need 4-5 generations of clutches with all pinstripe offspring to convince.)

doesn't mean its recessive, in fact, if thats the case it would be co-dom. Recessive means the heterozygous form does not show, which it obviously does, the spider we all have in our collections.

co-dom means the heterozygous and homozygous form are different. which if it was lethal, het would be spider and homozygous would be dead. still homozygous lethal anyways. the "XX" means homozygous, has nothing to do with recessive, co-dom, or dom.

Way I see it, it doesn't change the odds, sure it changes the ratio of things that actually come out of eggs, but as far as follicles go you still have the 1:2:1 ratio.

That's assuming its even homozygous lethal which there is next to nothing that suggests this lol.



There nothing that suggests that anything would happen to the eggs

You didn't understand what I said either. Read what I wrote above.

Also there are a lot of other types of genes that have the heterozygous and homozygous form as different traits. I'm not going to teach you all of them, you can go take a class on genetics for that.

I'm trying to understand what you're saying, but it's really confusing.

co-dom means the heterozygous and homozygous form are different. which if it was lethal, het would be spider and homozygous would be dead. still homozygous lethal anyways. the "XX" means homozygous, has nothing to do with recessive, co-dom, or dom.

I even got out my genetics notes for you.
Codominance means that both traits are present in the F1 generation but only one shows. A lot of ball python genes are actually Incomplete Dominant because when they are bred with another morph gene, they create a new mixture of the two.
We tend to use codominace for all of the traits, which is fine for layman terms most of the time but is incorrect for what you're saying.

It is lethal only in a homozygous dominant individual which makes the gene for lethality recessive, but the spider trait itself seems dominant in a heterozygous individual. If the homozygous individual was not lethal, then it would probably look the same since the gene acts dominant; but we don't actually know if it would show a codominant different trait since it's never been achieved.