Reptile & Amphibian Forums

I am seeing more and more ads for hets for a co-dominant trait, I am not questioning the sellers, just the facts. From what I've been able to gather, co-dominant morphs produce homo's and normals. Is it only some co-dom morphs that produce hets or is it just finally proving that hets are produced when everyone just dismissed them as normal siblings. Please edjucate me, Thank you very much for your time.

There are hets for co-dominant morphs, they just don't look normal.

Many people are confused about what heterozygous and homozygous really mean. Heterozygous means having an unmatched pair of whatever genes you are talking about (usually one mutant and one normal). Homozygous means having matching genes, either two normal or two mutant.

Because many snake people first learned about the term heterozygous with recessive mutations where the hets are normal looking they have gotten the mistaken belief that heterozygous means something like "normal looking gene carrier". However, since it really means having an unmatched pair of genes and doesn't by it’s self actually tell you what the snake looks (phenotype) like it is perfectly correct to talk about animals that are heterozygous for the pastel gene, spider, Mojave, or pinstripe genes. Basically these are animals that have one morph gene and one normal copy of the same gene. Unlike albino hets they don't look normal though.

If some day someone proves a homozygous spider or pinstripe and it looks just like the heterozygous ones we have seen so far then describing their genotype (heterozygous or homozygous mutant) will be the way to distinguish between them.

Another advantage of properly using the genotype terms is that you can use the same rules you learned to predict het breeding results for all morphs. You just need to remember the morphs type in the end to figure out the phenotypes. For example, you probably know that albino (homozygous) X het albino gives eggs with a 50/50 chance of being either albino or het albino. It works out the same for Leucistic (homozygous Mojave) X Mojave (het Mojave). Each egg has a 50/50 chance of being either homozygous Mojave (Leucistic) or heterozygous Mojave (regular Mojave).

Thank you very much, I learned a lot from your reply. I hope others read this and can learn from you as well.

It's not that big of a deal, just a pet peeve of mine.

Do watch out for normal looking "hets" for dominant type morphs.