Paul,



So if I understand your reasoning, because the salmon trait appears to not have a distinct visible homozygous recessive phenotype, it cannot be explained as a codominant trait. Is this correct?



I at no time claimed to be able to look at a trait and claim it was dominant, codominant or recessive. If I did, then I apologize. All I am seeking is to understand the genetics behind this trait.



I would argue that the Salmon trait (hypomelanism) is in fact codominant (the more accurate term might be haploinsufficiency). A dominant trait when bred to any other allele always expresses itself. If the salmon trait is dominant and you breed a salmon to a normal appearing b.c.i. then you would expect to see nothing but salmons in the f1 generation, no normals what so ever. Is this the case (I only ask as my salmon male - whom I suspect is a super salmon is too young to breed until next season so I don't know what the outcome would be)? What are the phenotypic ratios one gets in the f1 generation between this breeding? Do any normals appear? If so, then the trait must be codominant (haploinsufficient).



Haploinsufficiency, basically is a loss of function state. Whereby, the loss of function is variable, which could account for the varying degrees of expression seen in the breedings.



I'm just trying to understand what criteria were used to determine that the trait was dominant and what the test results were that bear that out.



Thanks,



Ian

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