great explaination as usual Randy...Originally Posted by RandyRemington
For some reason snake people tend to only use the genotype terms "heterozygous" and "homozygous" for recessive morphs but they actually apply for any mutation type. Breaking everything down to genotype has an advantage in that the same inheritance rules apply for all. You can then use the mutation type to figure out how the different inherited genotypes look relative to each other.
A pastel is heterozygous for the pastel mutation. “Heterozygous” means having an unmatched pair of whatever gene you are talking about. A pastel has one pastel mutant version and one normal for pastel version at the pastel gene location. Because pastel is not a recessive mutation the hets don't look normal but they are still heterozygous even though hardly anyone in ball pythons calls them that.
If you breed two pastels together the inheritance breakdown is just like any het X het breeding. Each egg has a 25% chance of being homozygous pastel (we call that phenotype super pastel), a 50% chance of being het pastel (regular pastel), and a 25% chance of being normal. It works exactly the same for breeding a pair of het albinos except that you can't tell the 50% chance hets from the 25% chance normals so lump them all together as 66% chance hets.
So, when you hear super think homozygous. That will also help you remember what happens when you breed super X normal. Just like homozygous albino X normal produces 100% het albinos a super pastel (homozygous) X normal produces 100% pastels (heterozygous). A homozygous animal only has one type for their two copies of that gene so will have to pass that one type on to all of their offspring unlike a het that has two types to pick from.
Super is a recently made up term so not sure if it requires that the homozygous animal looks different (more "super") than the heterozygous. The difference would only come up if we ever found a completely dominant ball python mutation. For example, if it turned out that a homozygous pinstripe is possible and it looks and acts just like the heterozygous pinstripes we have now (the visible pinstripes) then pinstripe would be proven to be a completely dominant mutation. But would you call the homozygous pinstripe a super or would you say there was no super pinstripe because the homozygous doesn't look more extreme than the regular heterozygous pinstripes?
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