An allelic series of miR-17∼92–mutant mice uncovers functional specialization and cooperation among members of a microRNA polycistron

ndrea Ventura and colleagues characterize an allelic series of genetically engineered mice harboring targeted deletions of individual members of the miR-17~92 cluster. They find evidence of functional cooperation and specialization among members of this cluster and show that the miR-17 seed family influences axial patterning.