Frequency and character of alternative somatic recombination fates of paralogous genes during T-DNA integration.
A synthetic RBCSB gene cluster was transformed into Arabidopsis in order to simultaneously evaluate the frequency and character of somatic illegitimate recombination, homologous recombination, and targeted gene replacement events associated with T-DNA-mediated transformation. The most frequent type of recombination event observed was illegitimate integration of the T-DNA without activation of the silent DeltaRBCS1B: LUC transgene. Sixteen luc(+) (firefly luciferase positive) T1 plants were isolated. Six of these were due to illegitimate recombination events resulting in a gene trapping effect. Nine resulted from homologous recombination between paralogous RBCSB sequences associated with T-DNA integration. The frequency of somatic homologous recombination associated with T-DNA integration was almost 200 times higher than previously reported rates of meiotic homologous recombination with the same genes. The distribution of (somatic homologous) recombination resolution sites generally fits a fractional interval length model. However, a small region adjacent to an indel showed a significant over-representation of resolution sites, suggesting that DNA mismatch recognition may also play an important role in the positioning of somatic resolution sites. The frequency of somatic resolution within exon-2 was significantly different from that previously observed during meiotic recombination.
Jelesko
John G
JG
Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA. jelesko@vt.edu
Carter
Kristy
K
Kinoshita
Yuki
Y
Gruissem
Wilhelm
W
D016960:Agrobacterium tumefaciens / Q000235:genetics; D000483:Alleles; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D001483:Base Sequence; D002678:Chimera / Q000235:genetics; D003433:Crosses, Genetic; D003434:Crossing Over, Genetic; D004269:DNA, Bacterial / Q000235:genetics*; D005091:Exons; D005786:Gene Expression Regulation; D008156:Luciferases / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000235:genetics; D011995:Recombination, Genetic; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics
D004269:DNA, Bacterial; D011994:Recombinant Proteins; C036483:T-DNA; D008156:Luciferases; D012273:Ribulose-Bisphosphate Carboxylase