Posted by:
Paul Hollander
at Fri May 26 11:59:38 2006 [ Email Message ] [ Show All Posts by Paul Hollander ]
>Forms of dominance: Codominance --- Simple Dominance --- Incomplete Dominance
Actually these are the three forms: dominance (AKA full dominance), codominance (synonyms: incomplete dominance, semidominance, partial dominance, transdominance, less than dominant, etc.), and recessive.
>As has been said, with codominance the heterzygous and homozygous forms (aka, non-"super" and "super" forms) are visually distinguishable ... different phenotypes.
>The way I understand it is that incomplete dominance creates a third phenotype that is a blending of the parental traits, ie red flower x white flower = pink flower.
In other words, red flower is the homozygous normal, white flower is the homozygous mutant (super in herper lingo), and pink flower is the heterozygous form. The heterozygous and homozygous forms are visually distinguishable making this an example of codominance.
I know that the texts often use this flower example as an example of incomplete dominance. In the strictest sense, the difference between a codominant and an incomplete dominant requires data on whether the mutant gene produces a functional product or not. This data is often unavailable. So we have to fall back on a looser definition in which "codominant" and "incomplete dominant" are synonyms.
>Not the case with hypos (you get hypos).
Right.
>So that rules out both incomplete dominance and codominance.
Right.
>someone please go into detail on the difference?
>
>as I understand it, Hypo is a dominant gene while motley is said to be co-dom. yet, both produce a "super form."
I define "super" as herper slang for the homozygous form of both dominant and codominant mutants. There are very few codominant and dominant mutants in snakes so far, and there has been a lot of misuse of standard genetic terms. Even NERD's page isn't 100%. You can delete "super" from your genetics vocabulary without any loss.
>how does this work, and where do arabasques fall in? supposedly arabasques are dominant, anybody proven it out yet?
Sorry, I don't know the answer to that question.
"Hypo" is a synonym for "salmon". There was a recent thread in the boa genetics, morphs, and locality subforum called $64 question on salmon boas where a lot of this was thrashed out. You ought to check it out. Link is below.
Paul Hollander
$64 question on salmon boas
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RE: co-dom vs. dominant - Paul Hollander, Fri May 26 11:59:38 2006