This article is from the WSSF 2015 AFRMA Rat & Mouse Tales news-magazine.

By Karen Robbins

Telisa Overton, e-mail
Q I have a Siamese male that is heterozygous for the Dumbo gene and a Black Berkshire female that has no tracings at all of the Dumbo gene in her history. I was wondering how I would get Dumbos from the resulting litter. Since the babies would carry the Dumbo gene from the sire and the standard gene from their dam, couldn’t I just breed one of the female pups back to the sire and get a small percentage of Dumbo rats?

A Only half will carry the gene since your male is not an actual Dumbo, but yes, you could breed a daughter back to dad and hope she is one that is a Dumbo carrier. You might want to keep back a couple females to try breeding back to dad. And of course even if they are carriers, you might not get Dumbo in the resulting litter even though on paper you should. It may take a couple breedings for it to show up, or you may get some right away.

Kenzie Est, Facebook
Q Do you have any tips about identifying if baby rats in the nest are Dumbo or Standard eared?

A Dumbos have the larger low-set ears and as babies the ears will point slightly away from the head. Also, when viewed from the side, the top or middle-top of a Dumbo ear will line up with the middle of the eye, whereas on a Standard, the middle or bottom of the ear will line up with the middle of the eye. So the best way is to compare each baby to see if you see any differences.

There are a couple old web sites with comparison photos of Dumbo vs. Standard ear baby rats: Spoiled Ratten Rattery (Elisabeth Brooks, archived page; middle of the page) and Fun Family CA Rodentry (Shuron Stover). Ashten Anthony with Sweet Whispers Rattery in PA has a photo in the Ears section of her Rat Varieties page.

There are a couple research articles online on the Dumbo gene:

• Expression of Msx1 and Dlx1 during Dumbo rat head development: Correlation with morphological features
• Deletion of a conserved regulatory element required for Hmx1 expression in craniofacial mesenchyme in the dumbo rat: a newly identified cause of congenital ear malformation that also has photos.

13-day-old Siamese rat kittens showing the placement of the ears in comparison to the eyes. Rats owned and bred by Elisabeth Brooks. Photo ©2002 Elisabeth Brooks.

13-day-old Siamese rat kittens showing how the Standard ears are next to the head whereas the Dumbo ears are set off the head. Rats owned and bred by Elisabeth Brooks. Photo ©2002 Elisabeth Brooks.

Back to top