Genetics 'n all

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Posted by Paul Hollander on April 29, 2003 at 18:46:24:

In Reply to: Genetics 'n all posted by sasheena on April 28, 2003 at 20:13:32:

:Thanks Paul, it's easy enough to change names later as some "authority" comes up with names. I've noticed in wandering around the JAX website that many genes have been renamed.

:I took the link you gave me and sort of put it together here, tell me if I have it right. I've also summarized and left a lot out, and added a few things. Dunno what it is about me, I just have to see little letters to figure out genes. :)

I find the letters helpful, too.

There are some things that can be improved.

Wild type phenotype -- The most common phenotype found in wild caught individuals. (IOW, a Miami phase may be wild caught, but it isn't wild type.) The wild type corn snake has a reddish brown (or brownish red) ground color, red blotches with a black edging along the back, a red spear mark on the top of the head, black pupils, orange/black/white checkering on the belly. This is only a partial description. The wild type phenotype is the standard. Mutant phenotypes are described by the changes from the wild type phenotype.

Wild type gene -- the allele at each locus that contibutes to the production of the wild type phenotype in some way.

:(snip)

:Anerythristic
:AX = normal amount of red pigment
:ax = Anerythristic� no red pigment, instead shades of gray, with some yellow present.

ax (Anerythristic) locus
ax⁺ = wild type allele. Somehow involved in producing the wild type phenotype. We do not know the exact function of the ax⁺ gene.
ax = Anerythristic� no red pigment, instead shades of gray, with some yellow present.

Traditional, textbook symbology for these two genes would be Ax and ax. Unfortunately, the textbooks have not kept up with the professional geneticists. I have followed the mouse symbol quidelines because (IMHO) they are well done, up to date, and used by the largest single group involved with vertebrate genetics.

The symbol for the wild type allele is the locus symbol with + as a superscript. See the mouse guidelines (below), section 3.1.3.

Dominant mutants have only the first letter of the symbol in upper case. See the mouse guidelines, section 3.1.1.

The definition of the ax⁺ gene can be repeated for the wild type allele at each locus. We have practically no knowledge of the function of each wild type gene.

:(snip)

:Blood Red
:PB = normal pattern
:pb = plain belly. (blood red). Normal dark checkering on the belly absent, blotches diffused.

br (Blood Red) locus
br⁺ = wild type allele. Somehow involved in producing the wild type phenotype. We do not know the exact function of the br⁺ gene.
br = blood red. Very little or no checkering on the belly, dorsal blotches diffused.

"Normal" is a synonym for "wild type", so I try to keep it out of the mutant phenotype descriptions.

Serpwidgets' comments are correct, AFAIK. He's seen and owned more corn snake mutants than I have.

Paul Hollander

guidelines for mouse genetic symbols

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