Response to selection for sensitivity to ethanol hypothermia: genetic analyses.

Selective breeding has been used to produce lines of mice differing in sensitivity to the hypothermic effects of ethanol (EtOH). Two genetically independent HOT (insensitive) and two COLD (sensitive) lines are maintained along with two nonselected control (CON) lines. The breeding program is currently in selected generation 14, and HOT and COLD mice differ by about 4 degrees C in selected hypothermic response. Estimates of heritability indicate that approximately 20% of the variance in EtOH-induced hypothermic response in mice is of additive genetic origin. Inbreeding has increased at a rate of about 1.7% per generation and no fertility problems have been detected as a result of selection. Projects designed to evaluate apparent correlated responses to selection are discussed.