This article is from the Sept./Oct. 1991 AFRMA Rat & Mouse Tales news-magazine.

By Troya Duncanson

Michele Buck, Rootstown, OH
Q Could you tell me if there is any way to breed for Fox or Tan mice using Chinchilla? Or do I just have to start with Fox or Tans which are already developed?

A Breeding Tan or Fox mice from Chinchilla mice should be very easy. Both Tan bellies and Fox bellies are caused by the same gene, the difference being that additional factors are required to dilute Tan all the way to Fox. And the easiest factor to work with is Chinchilla dilution! So in your first litter of Chinchilla crossed with almost any other mouse, you should get some Tan mice (Tan is a dominant trait). This litter will carry Chinchilla dilution, so if you continue to breed these Tan mice, Fox mice should periodically show up. Breed these Tan mice back to a Chinchilla mouse, and you should get Foxes and Tans in resulting litters (in addition to Agoutis, Chinchillas and Selfs).

ED. NOTE: For more on breeding Tan/Fox and Chinchilla mice, see the Oct. ’84, March/April ’85, March/April ’87 and Sept./Oct. ’87 issues.

Michael Emerson, Burnham, ME
Q I now have two four? colored mice. One is Black, Blue, Dove and Orange mis-marked on white with a Tan belly. The other, still in the nest, is an Agouti, Orange, English Gold and Lilac or Silver on white. I believe that genetically they are not Calico mice, but somehow the patches of color got diluted. They are from my Hairless line.

A Four colored mice? Wow. I hate to make any comments without seeing the mice. For patches of color getting diluted, I’d have to guess that your mice have Roan involved. I have seen two mice that were black and white, regular Broken type mice, except each had exactly one orange spot on the body. These mice unfortunately did not pass this trait on, and I don’t know what may have been involved. The breeder believes it was a somatic mutation in both cases (the new trait develops only in an isolated part of the body, not being carried in the rest of the body and not being able to be passed on to offspring). Does anyone else have comments on this one? I may have to hit the genetics books to find anything similar in lab stock. I would also have to see a picture of these guys.

ED. NOTE: This sounds quite interesting! We will definitely want to hear if these breed or if you get anymore. All the Tri-colors that I have known of to have popped up here are only 3 colors. There was only one Agouti rat with half Fawn face owned by Michelle Gallati. that I have known to reproduce itself. There were 2 rats that I have known of that were Tricolors, but I never did hear if any more were produced from them. I have heard that there are Tri-colored rats in the labs, but I don’t know for a fact. There is a strain of mice that are Tricolors (England had them for awhile and I understand they are here in a lab somewhere), but they have a Waltzing disorder associated with the gene and the British breeders eventually gave up on them after they couldn’t split up the 2 genes.

From Jessica Jakubanis, Norridge, IL
Q Is it possible to dilute black eyes and get brown eyes?

A I’m not aware of any way to dilute black eyes to brown eyes (I’m not sure that anything much darker than a hazel-brown would be very easy to distinguish from black anyway).

Chocolate mice have eyes that could be called dark ruby. With a strong back light they have a red cast. (The darker English mice may not even have this.) Other factors can dilute eyes to a ruby-red color, and of course there’s the pink-eye dilution that is named for turning eyes pink. At the moment, these are the only colors I’m aware of.

ED. NOTE: I have seen brown eyes in a rat once before. It was a Black Irish male owned by a breeder. I haven’t seen anything since.

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