A conditional knockout resource for the genome-wide study of mouse gene function

Knockout mice in which a specific gene is inactivated are central to the analysis of gene function. An important resource is reported here in the form of a high-throughput gene targeting pipeline that has already produced thousands of conditional mutations in the C57BL/6 embryonic stem-cell line, suitable for the creation of mutant mice for large-scale phenotyping programmes. The strategy is also applicable to rat and human stem cells and provides a foundation for deciphering the function of all genes encoded by the mammalian genome.