title: Homologous recombination: a basis for targeted genome optimization in crop species such as maize.
abstract: In an attempt to understand the feasibility of future targeted genome optimization in agronomic crops, we tested the efficiency of homologous recombination-mediated sequence insertion upon induction of a targeted DNA double-strand break at the desired integration site in maize. By the development of an efficient tissue culture protocol, and with the use of an I-SceI gene optimized for expression in maize, large numbers of precisely engineered maize events were produced in which DNA integration occurred very accurately. In a subset of events examined in detail, no additional deletions and/or insertions of short filler DNA at the integration site were observed. In 30%-40% of the recovered events, no traces of random insertions were observed. This was true for DNA delivery by both Agrobacterium and particle bombardment. These data suggest that targeted double-strand break-induced homologous recombination is a superior method to generate specific desired changes in the maize genome, and suggest targeted genome optimization of agronomic crops to be feasible.
authors.affiliation: Bayer BioScience N.V., Technologiepark 38, B-9052 Gent, Belgium. kathleen.d'halluin@bayercropscience.com
authors.forename: Kathleen
authors.initials: K
authors.lastname: D'Halluin
authors.forename: Chantal
authors.initials: C
authors.lastname: Vanderstraeten
authors.forename: Ellen
authors.initials: E
authors.lastname: Stals
authors.forename: Marc
authors.initials: M
authors.lastname: Cornelissen
authors.forename: Rene
authors.initials: R
authors.lastname: Ruiter
mesh_terms: D000613:Aminobutyrates; D053903:DNA Breaks, Double-Stranded; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics*; D018390:Gene Targeting / Q000379:methods*; D018745:Genome, Plant; D053209:Herbicide Resistance; D006540:Herbicides; D011995:Recombination, Genetic; D029701:Saccharomyces cerevisiae Proteins; D003313:Zea mays / Q000235:genetics*
chemical_list: D000613:Aminobutyrates; D006540:Herbicides; D029701:Saccharomyces cerevisiae Proteins; C003121:phosphinothricin; C037725:SCEI protein, S cerevisiae; D015252:Deoxyribonucleases, Type II Site-Specific