Parts and Pieces

Your normal mouse has a long straight tail, medium to large ears, and all the other “normal” parts and pieces. Some mice are missing some of their parts and pieces, and/or they have strange convolutions of those same parts. This is a very short section, but in truth there are a lot of genes that cause mice to change their parts and pieces, anywhere from multiple toes on their feet, to hammertoes, curly tails, fat tails, funny ears, etcetera. To find more of these genes a very fascinating resource is the Jackson Labs website.

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Description

bmp5^se

Chr. 9

found and photographed by Rachael

Short Ears Homozygotes have short, slightly ruffled external ears recognizable at about 14 days of age. These mice have other abnormalities of the spine, including fewer ribs, missing wrist and ankle bones, and other problems.

Grem

Chr. Un

Gremlin. A dominant gene with only limited penetrance. This mouse is notable for having one ear located on the side of its head while the other ear is located in the normal position.  

Grem^D

Chr. Un

Dumbo. Dumbo mice are an extension of the gremlin gene. Dumbo mice have two lowered ears usually recognizable by two to three weeks of age.

pr

Chr. Un

found and photographed by Rachael

Porcine Tail. Tail varies from a normal tail to a tightly looped tail as in a pig. Some of these mice show waltzing behavior.

t

Chr. 17

Tailless. The dominant gene T results in tailless mice T/~ are tailless. There are modifiers to the t gene which have several results: tⁿ/~ mice have normal tails. T/tⁿ mice are also tailless, and T/T and tⁿ/tⁿ mice are homozygous lethal.  Apparantly the t-type sperm has a tendency to fertilize more ova then non-t sperm, leading to a higher proportion of tailless mice than would be expected by mendelian genetics. This is perhaps responsible for the high incidence in the wild, despite its being homozygous lethal.