A new hybrid mouse model for agenesis of the corpus callosum.

A three locus model of the inheritance of absent corpus callosum in mice was tested by creating F1 and F2 hybrid crosses from the strains BALB/cWah1 and 129/J which show incomplete penetrance for callosal agenesis. The model predicted that a few of the F2 hybrid mice would suffer severe reduction of the hippocampal commissure when the corpus callosum was absent, a condition that usually occurs only in the most consistently acallosal I/LnJ strain, and this prediction was confirmed. The C129F2 hybrid population expresses substantial genetic variation and an extremely wide range of defects of the corpus callosum, dorsal commissure of the fornix and hippocampal commissure. At the same time, these hybrids have exceptionally good health and reproductive performance, unlike their inbred parent strains. These characteristics make them ideal subjects for the study of brain-behaviour correlation using a noninvasive method.