Identification of Transposon-Tagged Maize Genes Displaying Homology to Arrayed cDNA Clones with the Use of Mutator Insertion Display

Abstract

Transposon insertion mutagenesis is a powerful tool for understanding cereal gene function. Previous work has shown that Mutator-amplified fragment length polymorphism is an efficient and reproducible technique for amplifying sequences from individual plants, which flank the Mutator element. In this report, we show that by screening arrays of bacterial clones containing maize cDNA with amplified Mutator-flanking sequences, it is possible to rapidly identify expressed genes with sequence homology to Mutator-amplified fragments, along with individual plants containing the corresponding transposon insertion events. Using this technique, we have identified an average of eight expressed sequences per individual Mutator-active plant in a maize cDNA library prepared from 12-day post-pollination endosperm. Screening a maize leaf and a wheat endosperm cDNA library array confirmed that the procedure is capable of identifying Mutator-tagged genes that are expressed in a variety of tissues and/or related species. The majority of the cDNAs identified by the procedure showed significant similarity to sequences within the public database. Our study suggests that by using Mutator-tagged fragments to probe large numbers of arrayed cDNAs from a variety of sources, it is possible to rapidly generate a number of useful transposon-tagged genes, homologous expressed sequence tags, and the corresponding mutant plant lines. All of these materials will be extremely valuable for both future gene discovery and functional genomics programs.