This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bilang, R Articles by Paszkowski, J Search for Related Content PubMed PubMed Citation Articles by Bilang, R Articles by Paszkowski, J

Single-stranded DNA as a recombination substrate in plants as assessed by stable and transient recombination assays.

Institute of Plant Sciences, Swiss Federal Institute of Technology, ETH Zentrum, Zürich.

ABSTRACT

Two separate assays, one that requires stable integration of recombination products and one that does not, were employed to elucidate the role of single-stranded DNA in extrachromosomal homologous recombination in Nicotiana tabacum. Both assays revealed that single-stranded DNA in linear and in circular forms was an efficient substrate for recombination, provided that the cotransformed recombination substrates were of complementary sequence, so that direct annealing was possible. Recombination was inefficient when both single-stranded recombination partners contained homologous regions of identical sequence and generation of a double-stranded DNA was required prior to heteroduplex formation. These results indicate that direct annealing of single strands is an important initial step for intermolecular recombination in tobacco cells. Annealed cotransformed single-stranded molecules yielded intermediates that could be further processed by either continuous or discontinuous second-strand synthesis. The type of intermediate had no influence on the recombination efficiency. Double-stranded circles were unable to recombine efficiently either with each other or with single-stranded DNA. Our results suggest that a helicase activity is involved in the initial steps of double-stranded DNA recombination which unwinds duplex molecules at the site of double-strand breaks.

This article has been cited by other articles:

• Pacher, M., Schmidt-Puchta, W., Puchta, H. (2007). Two Unlinked Double-Strand Breaks Can Induce Reciprocal Exchanges in Plant Genomes via Homologous Recombination and Nonhomologous End Joining. Genetics 175: 21-29 [Abstract] [Full Text]  
• Zorin, B., Hegemann, P., Sizova, I. (2005). Nuclear-Gene Targeting by Using Single-Stranded DNA Avoids Illegitimate DNA Integration in Chlamydomonas reinhardtii. Eukaryot Cell 4: 1264-1272 [Abstract] [Full Text]  
• Puchta, H. (2005). The repair of double-strand breaks in plants: mechanisms and consequences for genome evolution. J Exp Bot 56: 1-14 [Abstract] [Full Text]  
• Siebert, R., Puchta, H. (2002). Efficient Repair of Genomic Double-Strand Breaks by Homologous Recombination between Directly Repeated Sequences in the Plant Genome. Plant Cell 14: 1121-1131 [Abstract] [Full Text]  
• Masson, J. E., Paszkowski, J. (1997). Arabidopsis thaliana mutants altered in homologous recombination. Proc. Natl. Acad. Sci. USA 94: 11731-11735 [Abstract] [Full Text]