How is IMPC data generated?

Mouse production and phenotyping is performed in a coordinated manner across the member research institutes. Coordination ensures (i) the elimination of duplicating mouse lines and phenotyping, thus keeping the number of mice used in research to the minimum necessary, and (ii) results are comparable across sites.

The IMPC pipeline involves six major steps (Figure 4).

1. Production. Mouse knockouts for a selected gene of interest are produced, that is, a mouse line is created that has a gene knocked out (‘switched off’ or inactivated); approximately 18,000 genes make up the mouse genome
2. Phenotyping. The physiology and morphology of the knockout mice is studied by applying standardised phenotyping methods, a collection of tests carefully chosen to study a range of biological systems; in addition, wildtype / baseline mice are also characterised in the same way (that is, mice for which no gene has been inactivated)
3. Statistical analysis. The results are statistically analysed by comparing knocked out and control (wildtype or baseline) mice
4. Annotation. When significant differences are identified between mutants and controls, these are attributed to the inactivation of the gene; when this occurs, a gene to phenotype interaction is established and the resulting (abnormal) phenotype is annotated with a Mammalian Phenotype Ontology term, e.g., “increased circulating LDL cholesterol level”
5. Quality control and data validation. A dedicated team of curators, developers and analysts review data for integrity and completion
6. Dissemination. The data and information on how to order IMPC-produced mice are displayed in the IMPC portal. Further, findings are disseminated in the form of scientific papers, press releases, popular science blog posts and social media campaigns