What ’ s Always Wrong with my Mouse ?

In recent years there has been a growing voice of concern that a considerable percentage of published scientific discoveries fail to replicate in subsequent studies. The issue is especially relevant to preclinical studies and animal models, and has recently led to reconsideration of policies by NIH [1], as well as by some scientific journals including Science [2] and Nature [3]. Behavioral phenotyping results especially seem to be sensitive, and studies comparing inbred strains and genetically-engineered mutants across laboratories demonstrated some disturbing discrepancies [4]. These discrepancies are all the more worrying in light of the current community effort, coordinated by the International Mouse Phenotyping Consortium (IMPC), to phenotype thousands of mouse mutant lines across many laboratories during the next several years, and make the results available in public databases [5], as part of a long-term goal to functionally annotate all mammalian protein-coding genes.