|
|
||||||||
|
First published online November 26, 2003; 10.1104/pp.103.027532 Plant Physiology 133:2061-2068 (2003) © 2003 American Society of Plant Biologists T-DNA Integration in Arabidopsis Chromosomes. Presence and Origin of Filler DNA Sequences1,[w]Department of Plant Genetics and Breeding, Center of Agricultural Research-Gent, Caritasstraat 21, B-9090 Melle, Belgium (P.W., E.V.B., M.D.L.); Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology, Ghent University, Technologiepark 927, B-9052 Gent, Belgium (S.D.B., A.D.); and Department for Plant Production, Ghent University, Coupure Links 653, B-9000 Gent, Belgium (E.V.B.)
To investigate the relationship between T-DNA integration and double-stranded break (DSB) repair in Arabidopsis, we studied 67 T-DNA/plant DNA junctions and 13 T-DNA/T-DNA junctions derived from transgenic plants. Three different types of T-DNA-associated joining could be distinguished. A minority of T-DNA/plant DNA junctions were joined by a simple ligation-like mechanism, resulting in a junction without microhomology or filler DNA insertions. For about one-half of all analyzed junctions, joining of the two ends occurred without insertion of filler sequences. For these junctions, microhomology was strikingly combined with deletions of the T-DNA ends. For the remaining plant DNA/T-DNA junctions, up to 51-bp-long filler sequences were present between plant DNA and T-DNA contiguous sequences. These filler segments are built from several short sequence motifs, identical to sequence blocks that occur in the T-DNA ends and/or the plant DNA close to the integration site. Mutual microhomologies among the sequence motifs that constitute a filler segment were frequently observed. When T-DNA integration and DSB repair were compared, the most conspicuous difference was the frequency and the structural organization of the filler insertions. In Arabidopsis, no filler insertions were found at DSB repair junctions. In maize (Zea mays) and tobacco (Nicotiana tabacum), DSB repair-associated filler was normally composed of simple, uninterrupted sequence blocks. Thus, although DSB repair and T-DNA integration are probably closely related, both mechanisms have some exclusive and specific characteristics.
1 This work was supported by the European Community (grant no. 18687-2001-11), by the European Union BIOTECH program (grant no. QLRT-2000-00078), and by the Fund for Scientific Research Flanders (G.0118.01). [w] The online version of this article contains Web-only data. Article, publication date, and citation information can be found at www.plantphysiol.org/cgi/doi/10.1104/pp.103.027532. * Corresponding author; e-mail ann.depicker{at}psb.ugent.be; fax 32-9-3313809. Received May 26, 2003; returned for revision July 20, 2003; accepted August 21, 2003. This article has been cited by other articles:
|
|||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ASPB Publications | PLANT PHYSIOLOGY® | THE PLANT CELL | |
|---|---|---|---|