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.