Functional Genomic Analysis of Transposon Insertion Mutant Maize Plants from the UniformMu National Public Resource

Abstract

The UniformMu National Public Resource is a widely used, functional genomics tool for maize, constructed by backcross introgression of active Robertson's Mutator (Mu) transposons into the W22 inbred line, creating a large, searchable collection of lines that together carry transposon insertions in thousands of maize genes. This resource provides (1) a ready supply of freely available mutant seed stocks, each linked to mapped gene sequences; (2) uniform controls in an inbred background, for precision analysis of mutant phenotypes; (3) a reliable source of heritable mutants that are consistently recovered in stated lines; and (4) stable mutant lines with no Mu activity. This low-cost resource provides a consummate experimental system for linking gene sequences with their function in a species that has long served humanity, not only as a preeminent genetic model, but also as one of the world's most productive grain crops. Here, we describe how to perform an initial, online search of insertions in the UniformMu population, request seeds, generate segregating families, PCR-genotype seedlings for Mu insertions of interest, and associate genotypes with phenotypes. Resulting analyses provide definitive, in planta evidence for genotype–phenotype relationships that either support or refute hypotheses regarding gene function.