John C. Crabbe
As in any area of science, investigators seek to reproduce interesting results of behavioral and other neurobiological experiments with laboratory animals in their own laboratory setting. This generalization of research findings is a crucial part of the scientific process in several ways. Reproducibility, in the broad sense, is taken as a sign of reliability. Failures to reproduce a finding can help to prune the literature of false-positive findings. Successful exportation of a finding to multiple laboratories can allow a scientific insight to be explored using diverse methods not available to the original reporter. In the specific case of studies with stable, reproducible genotypes, the accumulation of results across laboratories is both spatial and temporal. Thus, one of the most long-standing (and reproducible) findings in the modern history of studies with inbred mouse strains is the repeated finding that inbred mice of the C57BL lineage prefer to drink alcohol solutions over plain tap water, and those of the DBA lineage are near-teetotalers, while many other inbred strains show intermediate levels of preference for alcohol (Belknap and others 1993; McClearn and Rodgers 1959; Rodgers 1972; Wahlsten and others 2003a).
However, it is nearly impossible to replicate an experiment exactly. For behavioral studies with laboratory mice, the subject of this paper, it is flatly impossible. Interest in behavioral genetics and genomics is on the rise, driven by the revolution in genomic and informatics capabilities. One of the simplest meaningful behavior genetics experiments with mice is to compare multiple inbred strains on the same task. Within a strain,