Selective breeding for a multivariate index of ethanol dependence in mice: results from the first five generations.

Starting with a population of genetically heterogeneous mice (HS/lbg), selection for a multivariate index of the ethanol withdrawal syndrome has been initiated. The study uses within-litter selection to minimize inbreeding and includes replicate high, low, and control lines. After five generations, results indicate that selection is proceeding successfully. There is evidence of asymmetry in the selection, i.e., selection is proceeding more rapidly for signs of severe withdrawal than for mild withdrawal signs. The realized heritability after five generations of within-family selection is approximately 0.15. These selected lines should eventually prove useful in determining some of the underlying genetic, physiological, and biochemical mechanisms involved in ethanol dependence.