title: Palindromic sequences and A+T-rich DNA elements promote illegitimate recombination in Nicotiana tabacum.
abstract: Illegitimate recombination is the prevailing molecular mechanism for the integration of recombinant DNA into the genome of most eukaryotic systems and the generation of deletions by intrachromosomal recombination. We developed a ?selectable marker system to screen for intrachromosomal illegitimate recombination events in order to assess the sequence and structure-specific requirements for illegitimate recombination in tobacco. In 12 illegitimate recombination products analysed, we found that all deletion termini localise to sites of palindromic structures or to A+T-rich DNA elements. All deletion termini showed microhomologies of two to six nucleotides. In three plants, the recombination products contained filler-DNA or an inversion of an endogenous segment. Our data strongly suggest that illegitimate recombination in plants is mediated by a DNA synthesis-dependent process, and that this mechanism is promoted by DNA regions that can form palindromic structures or facilitate DNA unwinding.
authors.affiliation: University of Leeds, Leeds, LS2 9JT, UK.
authors.forename: A E
authors.initials: AE
authors.lastname: Müller
authors.forename: Y
authors.initials: Y
authors.lastname: Kamisugi
authors.forename: R
authors.initials: R
authors.lastname: Grüneberg
authors.forename: I
authors.initials: I
authors.lastname: Niedenhof
authors.forename: R J
authors.initials: RJ
authors.lastname: Hörold
authors.forename: P
authors.initials: P
authors.lastname: Meyer
mesh_terms: D000241:Adenosine / Q000737:chemistry; D020029:Base Pairing; D001483:Base Sequence; D018744:DNA, Plant / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010947:Plants, Toxic; D016133:Polymerase Chain Reaction; D011523:Protoplasts / Q000502:physiology; D011995:Recombination, Genetic; D012689:Sequence Homology, Nucleic Acid; D013936:Thymidine / Q000737:chemistry; D014026:Nicotiana / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D000241:Adenosine; D013936:Thymidine