Can I get anything with Het spider???

Quote:

---

Originally Posted by alilshadee

Thanks all!! I just got confused b/c on the website they were calling the spiders hets and then they had a super spider and called it the homozygus.

(I slept thru Biology in highschool)

---

Calling the spiders hets? Maybe you had that confused with spiders that are hets... meaning, they are spiders that are het for albino for example?

there are 4 main diffrent kinds of ways that certain morphs can be expressed
1. reccesive this means that you need the animal to homozygous to show the trait. However if it it is heterozygous or a het it will look normal but have the gene. if you breed two hets you have a 1 in four chance per egg of producing a visual baby of a baby that is homozygous. for example if i had two normal looking snakes het for albino and i breed them each egg i produced would have a 1 in 4 chance of being an albino baby so in a perfect world if i produced a clutch of four eggs one of those would be albino.

2. dominant in dominat traits there are no hets so your snake must be one that is a visual morph to produce other visuals. these morphs are often more common because they are easier to produce.

3. Co-Dominant this is pretty much the same as dominat except that if you have a snake that has a co-dominat trait and breed it with a snake that is dominant both traits will show up together in the offspring I.E the traits dominat togther hence the CO.

4. Incomplete Dominace- this is much more complicated the easiiest example is when you have two flowers, a white and a red flower, and you breed them the ofsrping will show a blend of the two traits so the babys would be will be PINK.

sorry for the long post some of this may be unclear as i am not the best one to explain but if you have any other questions you can PM me. Good luck :carrot:

Quote:

---

Originally Posted by ReptileFan

2. dominant in dominat traits there are no hets

---

NO, NO, NO. How can I make this any clearer? Sorry I'm not trying to pick on you ReptileFan. But I see this a lot on here and other herp forums.

The mutation or trait type (dominant, recessive, etc.) is completely different thing than the genotype of an organism. There are two basic words used to describe genotype (heterozygous or homozygous).

For example, pastel is a co-dominant morph. When you breed two pastels together you have a 25% chance of getting a superpastel. This is because Pastels are heterozygous for the Pastel gene (Pp). The trait doesn't suddenly change to being a dominant trait when you get a superpastel--its just that the superpastel is the homozygous form (PP).

It is crucial to understand the difference between mutation or trait type and genotypes if you are to harness the predictive power of Mendelian genetics. If you understand Mendelian genetics, you can design crosses that will have better chances of producing the traits you desire.

Pasteur said it best when he said, "Chance favors the prepared mind". :)

I know what you were getting at....but you should qualify what you say. In dominant or co-dominant traits, there are no non-visually or normal-looking hets.

Last part to should read...

"In dominant or co-dominant traits, there are no non-visual or normal-looking hets."

One more thing I'll point out.....your right that technically co-dominance and incomplete (partial) dominance are two separate things. But at the macroscopic level that herptoculturists work at you cant really distinguish between the two.

The only way you can distinguish the two is by looking at the molecular genetics and biochemistry of the genes involved. I think herpers have choose to use "co-dominant" over "incompletely dominant" because it's less wordy.

I really do think it will be less confusing in the long run if we learn that heterozygous (aka "het") means having an unmatched pair of genes at whatever location you are talking about and does NOT mean normal looking gene carrier, it just happens to work out that way with the recessive morphs most of us learned about first. With co-dominant and completely dominant mutations the hets are visible morphs.

Predicting the offspring of a cross is much easier if you first know the genotype. Because all or most of the spider phenotype animals seen so far have the heterozygous for spider genotype we know they have one spider version of the gene at the spider location and one normal for spider allele (version of a gene). Knowing that they are heterozygous for the spider gene it's easy to see how each offspring has a 50/50 chance of getting the spider mutant version or getting the normal for spider version from that parent.

Now in the case of a super pastel, at the pastel locus it only has one type - pastel, with no room for a normal for pastel version. So knowing that the super pastel is homozygous pastel you can see how there is a 100% chance of it passing the pastel mutant version of the gene to each of its offspring. It doesn’t have any other type of that gene to give.

I'd also like to agree that we should try to stamp out using phrases like "dominant form" to refer to homozygous animals. Pastel is a co-dominant (or as noted it might be incomplete dominant for all we know) mutation type because the heterozygous and homozygous pastels are both morphs and look different from each other. It doesn't suddenly become a dominant type mutation when you are looking at a super pastel. It's the genotype that has changed, from heterozygous pastel to homozygous pastel. The mutation type is describing the relationship between they way the two genotypes look and doesn't change from animal to animal.

AWSOME scientific explanation and clarification, mendel and randy!!!

~mike

Mendel, where in PA are you? West or east?

Western PA near Pittsburgh.

Go Pens! (Sorry about them Flyers......) LOL