An early-onset congenic strain of the motor neuron degeneration (mnd) mouse

The mouse mutant motor neuron degeneration (mnd/mnd) has been proposed as a model of neuronal ceroid lipofuscinosis (NCL) on the basis of widespread a bnormal accumulating lipopigment and neuronal and retinal degeneration. Cli nically, the mutant on a C57B1/6 genetic background shows or progressive mo tor abnormality starting by 6 months of age, with death prier to 12 months. When mnd is outcrossed to the AKR/J genetic background, ea, 40% of the mnd /mnd F2 progeny show early onset (onset by 4.5-5 months and death by 7 mont hs). A congenic strain of mnd has now been produced by eight generations of backcross onto the AKR background, Mice on this background show average on set at 4 months, and most are moribund prior to 5.5 months. The early onset appears to correlate with levels of abnormal accumulating material, and sh ould prove useful in elucidating NCL neurodegenerative mechanisms. (C) 1999 Academic Press.