American Fancy Rat & Mouse Association

This article is from the Sep./Oct. 1995 AFRMA Rat & Mouse Tales news-magazine.

Colors & Coats

Odd-Eye Rats; Siamese Mice
Odd-Eye Rats

Liz Landsman, Arroyo Grande, CA
QDoes anybody know how the genetics work on odd-eye rats? If you have only one rat with odd eyes, can you mate him with either black-eyed or pink-eyed to get odd-eyed offspring? Also, how soon would it take for the eye color to show? I believe in human babies they start out with blue eyes and it takes 6 months for their true color to show, so I was wondering if the same is true for rats.

ANot much is known about the odd-eye gene. What we do know is that it is recessive. If you only have one odd-eye rat to start with, you have to breed it to a normal-eyed rat, and then breed the offspring back to the odd-eyed parent or to each other. Then you have to have patience, it may take several breedings before you see any odd-eyes. Even when breeding two odd-eyed rats together it is not unusual to only get one odd-eye in the litter. Odd-eyes will only show up in the colors which can have either light or dark eyes, and you will want to keep this in mind when choosing the normal-eyed rat to breed with your odd-eye. Fawn, Beige, Coffee, Lilac, and Cinnamon are the colors in which you can expect odd-eye. With most odd-eyed rats, the difference in eye color can be seen as soon as they open their eyes, but sometimes it can take as long as a week before the difference becomes evident. Nichole Royer

Siamese Mice

Richard Gilliam, Bremerton, WA
QI am interested in breeding Siamese mice and would like to know what colors in mice to use.

ATo breed normal Seal Point Siamese you will want to outcross on occasion with Black Self mice to darken the point color. To make Blue Point Siamese, you will need to cross a Seal Point Siamese with a Blue Self, and then take the F1 generation and breed those to each other. One in sixteen should be a Blue Point. You would also follow these same guidelines to make other point-colored Siamese, although keep in mind that some colors don’t look very nice or are very pale. Fawn Point is one color that is genetically impossible to produce. Karen Robbins *

July 12, 2014