The UniformMu National Public Resource: Transposon-Induced Mutant Seeds for Functional Genomics Studies in Maize

Geneticists frequently use loss-of-function (knockout) mutations to reveal the effects of a gene's dysfunction at the organismal level, observed as the mutant phenotype. This strategy is facilitated by creation of large, searchable collections of knockout mutants in an organism of interest. Paramount among such resources in maize is the UniformMu National Resource, a large collection of genetic stocks carrying mutations generated by insertions of Robertson's Mutator (Mu) transposons. The name UniformMu refers to the phenotypic uniformity of the W22 inbred genetic background in which Mu insertion mutants were created. This community resource continues its pivotal role in providing seeds containing beneficial knockout and knockdown mutations in targeted genes, which can be used to elucidate gene function. The resource offers an invaluable complement to other functional genomics approaches aimed at bridging the gap between genome sequences and plant performance in the field. Several key features are central to the success of the UniformMu National Public Resource. First, mapped insertions are linked to seed stocks that are readily available through the Maize Genetics and Genomics Database (MaizeGDB) and the Maize Genetics Cooperation Stock Center. Second, a uniform inbred background facilitates analysis of mutant phenotypes, by providing uniform wild-type controls. Third, mutant alleles are reliably heritable and consistently recovered in stated lines. Finally, lines are stable, with no continuing transposition of Mu insertions. The collective effort of the maize community allows UniformMu to provide readily accessible knockout and knockdown mutant seeds, as well as, ultimately, highly sought evidence for gene function in planta.