Posted by:
Paul Hollander
at Fri May 26 13:49:47 2006 [ Email Message ] [ Show All Posts by Paul Hollander ]
>I think that since the Hypos have so much variability within a litter between both heterozygous and homozygous forms, and since they contribute variably when combined with other mutations that the incomplete dominance label is fitting. Obviously in cases such as this, we are left to label the mutation the best way we can, and this is really only done for understanding on a common basis.
The variability when combined with other, independent mutants doesn't really count in the dominant-codominant-recessive classification. Salmon (Hypo) is obviously not a recessive mutant gene. Salmons have so much variability within a litter between heterozygous and homozygous forms that often they cannot be separated. That's why I think that salmon is better classed as a dominant mutant gene than a codominant mutant gene. I know that Rich Ihle called salmon an "incomplete dominant". I'd agree with him only if he can distinguish homozygous salmons from heterozygous salmons with 95% or higher accuracy and can teach others to do as well.
Codominant mutants and incomplete dominant mutants can only be distinguished with data showing whether or not there is a functional gene product. We have no such data for salmon and most other snake mutants; we only have breeding data. Breeding results are exactly the same for incomplete dominants and for codominants, making the terms synonyms at this level. My genetics prof used "codominant" as a catchall for all mutants producing this sort of breeding result because it has fewer characters to type than "incomplete dominant".
If he can't do a better job
Paul Hollander
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RE: Ryan... - Paul Hollander, Fri May 26 13:49:47 2006