>If this genetic crossover plays havoc with the melanin....and the Motley being mainly a form high in melanin...that if the melanin was shut off genetically would not the hypos take on a super hypo form? Now would this animal still reproduce both forms??

As far as I know, we have no reason to believe that motley and salmon are located on the same chromosome. Even if they are on the same chromosome, crossover is not necessary to explain things.

Albino shuts off melanin production. Combining albino and salmon produces sunglow, which is lighter than super salmon. It would be interesting to see what an albino, salmon, motley combination produces.

For what it's worth, every genetic combination I've worked with could be taken apart.

>The following is just pasted in from something I found....
>
>Gene Function and mutant alleles

If this piece was a bridge, it would be like one of the bridges that Indiana Jones keeps finding, the type thrown together from rotting planks and ropes frayed to a thread. Let's examine the last paragraph. By the way, the piece is about Budgerigars, which are not among the genetically best-known organisms.

>As more colour morphs are discovered in each species, multiple allelic series are becoming increasingly identified.

Pretty generally true, as far as I know.

>This is to be expected because there is a limited number of loci involved with pigment control and therefore limited places where a mutation can occur.

Again true, though "limited number" was 50 in mice around 20 years ago. It's probably higher, now.

>So far no allelic series is known for loci with dominant or co-dominant mutant alleles, only those with recessive mutant alleles.

I don't know about budgerigars. It's not true in mice or pigeons, to name only two species.

>And in all known cases a dominance hierarchy is formed within the allelic series.

Again true, as far as I know, even in the series containing dominant and codominant mutants.

>Mutant alleles with greater function (closer to wildtype) are either dominant or co-dominant with alleles with less function. I know of no situation where less functional alleles are dominant to other alleles in a series.

What is the definition of "greater function"? Whetever it means, I don't think it agrees with my experience with the dominant yellow mutant in mice.

Dominant yellow in mice is codominant to the other alleles at the a locus. A mouse with two dominant yellow mutant genes dies before it is a day old. A mouse with a dominant yellow mutant paired with one of the other alleles gets fatter and has fewer babies than normal mice. Whatever the dominant yellow mutation actually does, it clearly produces a mouse with a survival disadvantage.

Paul Hollander

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