Posted by:
Paul Hollander
at Mon Sep 11 18:06:01 2006 [ Email Message ] [ Show All Posts by Paul Hollander ]
>so, the hypo/salmon gene is just "dominant"!? If it was a simple dominant then an animal would either be hypo/salmon, or not. And it would either pass it on, or not. There would be no such thing as a "super salmon" with extra markers (more reduced pattern) than a regular salmon.
The problem is that while many salmons with a pair of salmon mutant genes have the extra markers, many do not. This sort of thing is called "variable expressivity" and shows up every so often. So the question becomes, where do you draw the line? In my opinion, if at least 95% of the salmons with one salmon gene can be distinguished from those with two salmon genes, then salmon would best be classed as a codominant mutant gene. People on these forums say that nobody can do anywhere close to that. So I think that "dominant" is a better classification than "codominant" for this mutant gene. It is certainly not a recessive mutant gene.
>(much snipped) The "Super" is a dominant form of a co-dominant gene, and can be bred to a normal animal to produce entire clutches of the visible het, or co-dominant form.
This is the sort of vocabulary fostered on many herper web sites. Which is why I label them "dreadful" and recommend learning genetics from a text.
"Super" is herper slang unknown in standard genetics. A "super" is homozygous for a codominant gene. Or sometimes for a dominant gene. Some genes are codominants and some are dominants, but there is no such thing as a snake that is either the "dominant form" or the "co-dominant form". A snake that has a salmon mutant gene paired with a normal gene is heterozygous for salmon, a dominant mutant gene. A snake that has a pair of salmon mutant genes is homozygous for salmon, a dominant mutant gene. All the babies from a homozygous salmon x normal mating are heterozygous salmons and show the salmon phenotype.
Paul Hollander
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