Reptile & Amphibian Forums

Ok everyone i have some questions; When i grow older i plan to breed balls as a hobby; but right now i may want to invest a little. I get basic genetics fairly well, such as dominant, recessive, punnet squares, heterozygous, homozygous, albino (melanistic), hypomelanistic, hypermelanistic, etc. But with BPs im unsure of such things as Codominance, and how you could cross morphs, such as MKR's new Pastave, which i absolutely adore them for, and like Bumble bee spiders...can anyone greatly enlighten me, (I.E. Explanation and Examples pf the following: Codominant morphs; Recessive Morphs; Dominant Morphs; Crossing Morphs; etc.)
Thanks!
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Nic
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The main thing to keep in mind is that animals have two copies of each gene (except for sex linked genes) and that each parent randomly gives a copy of one their two copies of each gene to the offspring (two parents so the baby ends up with two copies of each of the many genes).

With this understanding you can see how genotypes work (i.e. homozygous X normal = heterozygous etc.). Just remember the possible genes they could have gotten from each of their parents.

Once you understand genotype inheritance then you just need to know about the types of morphs out there. With recessive, the hets are supposed to look normal and only the homozygous look like mutants. With co-dominant/incompletely dominant the hets are mutants but the homozygous are different looking mutants (usually more extreme examples of the hets). With completely dominant mutations the hets and the homozygous are both mutants but look the same.

As far as combining mutations it's generally a matter of just overlaying the possibilities for each gene independently. In general, each morph is a different gene and independent from other morphs (however, it is possible for there to be a connection but we'll worry about that later). When you breed a homozygous axanthic to a homozygous albino you get all normal looking double hets. This is because, if you just look at the axanthic gene, you are breeding a homozygous to a normal (normal for axanthic, doesn't mater that it's albino, a different gene location). On the other hand, from the albino perspective you are breeding an albino to a normal. So if it was an axanthic male X an albino female then all the babies would get an axanthic gene from the father and a normal for axanthic copy of the same gene from the mother. However, they would all get an albino copy of the different gene (there are very very many genes) from mom and a normal copy of the gene corresponding to albino from dad.

It does get a little trickier once you start considering the possibilities that genes are on the same chromosome or are alleles (different mutations of the same gene) and then there is the possibility of a sex linked gene but none of these have been proven in ball python morphs yet.