Mice homozygous for the hotfoot 18 Jackson mutation have a staggering gait with hesitant placement of the feet, similar to that seen for other hotfoot mutants. Auditory brainstem response assessment of one homozygote and one sibling control mouse at 107 days of age showed that the homozygote was deaf. Homozygous females breed, yet males failed to reproduce. However, cryopreserved sperm from homozygous males can be thawed successfully and used for in vitro fertilization to produce heterozygous pups.
The hotfoot 18 Jackson mutation arose spontaneously at The Jackson Laboratory in early 2011 in the strain B10.D2-Hc1 H2d H2-T18c/nSnJ and was backcrossed to C57BL/6J by repeated backcross-intercross breeding. In 2013 sperm was cryopreserved from homozygous males at backcross generation N4 and will be recovered by in vitro fertilization using C57BL/6J oocytes so recovered pups will be at backcross generation N5.
|Allele Name||hotfoot 18 Jackson|
|Allele Type||Spontaneous (Not Specified)|
|Gene Symbol and Name||Grid2, glutamate receptor, ionotropic, delta 2|
|Strain of Origin||B10.D2-Hc1 H2d H2-T18c/nSnJ|
|Molecular Note||Exome sequencing of this spontaneous mutation indicated a deletion encompassing exons 3 and 4 and RT-PCR of RNA extracted from brain tissue revealed aberrant transcript for this gene.|