XVI International Botanical Congess

Chimeraplasty, a technology using chimeric DNA/RNA oligonucleotides to effect nucleotide conversions in DNA sequences has been successfully adapted for targeted manipulation of endogenous genes in maize. In this presentation, we demonstrate three examples in which site-specific heritable mutations were engineered in maize genes. The efficiency of gene conversion mediated by chimeric oligonucleotides in our system was estimated as 10-4, 2-3 orders of magnitude higher than frequencies reported for gene targeting by homologous recombination in plants. The heritable changes in maize genes engineered by this approach create new opportunities for basic studies of plant gene function and agricultural trait manipulation, as well as providing a system for studying mismatch repair mechanisms in maize.