title: Spontaneous mutation frequency in plants obscures the effect of chimeraplasty.
abstract: In this study we tested the performance of chimeraplasts, chimeric RNA/DNA oligonucleotides, for the creation of directed changes in chromosomal sequences in tobacco and oilseed rape. As target genes for chimeraplasty, the endogenous als gene and two transgenes, bar and a fusion between egfp and bar, were used. In experiments in which similar numbers of cells were treated with and without chimeraplasts, delivery of chimeraplasts did not lead to increased numbers of herbicide-resistant or egfp fluorescent calli. Sequence analysis of the target genes revealed a range of sequence changes rather than the sequence modification intended through chimeraplast design. Importantly, in both the presence and absence of chimeraplasts, similar types of changes were obtained at similar frequencies. These data suggest that the observed changes at the target codon result primarily from spontaneous mutation.
authors.affiliation: BioScience Research, Bayer BioScience N.V., Jozef Plateaustraat 22, 9000 Gent, Belgium.
authors.forename: René
authors.initials: R
authors.lastname: Ruiter
authors.forename: Ilse
authors.initials: I
authors.lastname: van den Brande
authors.forename: Ellen
authors.initials: E
authors.lastname: Stals
authors.forename: Stijn
authors.initials: S
authors.lastname: Delauré
authors.forename: Marc
authors.initials: M
authors.lastname: Cornelissen
authors.forename: Kathleen
authors.initials: K
authors.lastname: D'Halluin
mesh_terms: D001483:Base Sequence; D019470:Biolistics; D029688:Brassica napus / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D004351:Drug Resistance / Q000235:genetics; D005787:Gene Frequency; D006540:Herbicides / Q000494:pharmacology; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics*; D010944:Plants / Q000187:drug effects / Q000235:genetics*; D030821:Plants, Genetically Modified; D013449:Sulfonamides / Q000494:pharmacology; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D019076:Transgenes / Q000235:genetics; D014227:Triazines / Q000494:pharmacology
chemical_list: D006540:Herbicides; D013449:Sulfonamides; D014227:Triazines; C037137:chlorsulfuron