Genetics experts please help

[onebreitgirl]

I've been researcing color genetics in rats for a few months now but there is one locus I don't understand...Pearl.

I know it is linked with mink, but how do you create Pearls without the actual mink coloring? Does the mink have to be diluted with another trait? I'm assuming this is how blue pearls are made?

I have a mink breeder male that I assume has the pearl gene because the base of his coat is white and he's silvered all over. Trying to figure out what to breed him to in order to create pearls down the road.

[littleindiangirl]

http://jhered.oxfordjournals.org/cgi...tract/85/2/142

Two new coat color mutants are described. These are mink (symbol m) and pearl (symbol Pe). Mink produces a light brown coat, with variable white undercolor, and is inherited as a recessive to type. Pearl produces both a white coat and one that is pale cream with variable dark brown tips to the hairs. Gene Pe is inherited as a dominant and is lethal when homozygous. The pearl gene is hypostatic to other color genes, and the phenotype is only produced in conjunction with mink in the genotype mmPe+. The agouti (A) and pearl loci are found to be closely linked, with a recombination percentage of 0.73 ± 0.42.

http://www.neratsociety.co.uk/images.../genetics2.htm

Pe locus, the pearl locus. The allele Pe that produces a noticeable effect is dominant but only shows itself in an mm rat (mink or cinnamon) where its effect is to bleach the base of the hair leaving the mink colour only at the tip. A ‘mink’ rat with a pearl allele, is a pearl, a ‘cinnamon’ rat with a pearl allele is a cinnamon pearl. This allele Pe is ‘homozygous lethal’, that is, rats that get Pe from both parents and so would be PePe are not born.

You can't just make a pearl, you rat needs to carry it, and it is described as a dominant gene. (Although there is rumor that it is recessive, although that gene could be entirely different)

[littleindiangirl]

Found three very good pictures of the variability of pearls for you. All three are genetically the same, but have quite different contrasts. Am I just confusing you more?

http://goto.glocalnet.net/rat/gen/zxpearl.htm

The genetics as describe on this page to make a pearl is aa,mm,Pepe

[onebreitgirl]

Thanks for the links...I'm still confused...LOL!

I guess it's just different modifiers on the genes that make the different colors. I want to make one like the first rat pictured...Guess I will just have to keep playing around and see what happens

[littleindiangirl]

The confusion may be the differences between the color pearl, and the actual pearl " Pe" gene.

The color "pearl" is genetically a mink, with the pearl gene, since the pearl gene will only show up on the mink coat. (or cinnamon, which is a mink agouti).

Those pictures on the link are all "Mink Pearls", but there is such a difference in between them, they chose to name the very darker version the "silver mink". And the dark pearl is still the effects of the same genotype, but is also darker than the lightest pearl image at the top.

Genetically they all carry the exact same genes, and I'm not sure if it is modifiers at work that create the saturation of pearl gene... I have never looked too deeply into it. All I clearly remember is the homozygous lethal.

Michelle C. or SatanticIntention would know better than me on the pearl gene.