Premium
The DNA sequences of T‐DNA junctions suggest that complex T‐DNA loci are formed by a recombination process resembling T‐DNA integration
Author(s) -
De Buck Sylvie,
Jacobs Anni,
Van Montagu Marc,
Depicker Ann
Publication year - 1999
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1999.00602.x
Subject(s) - dna , recombination , genetics , biology , dna sequencing , gene
Summary After Agrobacterium ‐mediated plant transformation, multiple T‐DNAs frequently integrate at the same position in the plant genome, resulting in the formation of inverted and direct repeats. Because these inverted repeats cannot be amplified and analyzed by PCR, Arabidopsis root cells were co‐transformed with two different T‐DNAs with distinct sequences adjacent to the T‐DNA borders. Nine direct or inverted T‐DNA border junctions were analyzed at the sequence level. Precise end‐to‐end fusions were found between two right border ends, whereas imprecise fusions and filler DNA were present in T‐DNA linkages containing a left border end. The results suggest that end‐to‐end ligation of double‐stranded T‐DNAs occurs especially between right T‐DNA ends and that illegitimate recombination on the basis of microhomology, deletions, repair activities and insertions of filler DNA is involved in the formation of left border T‐DNA junctions. Therefore, a similar illegitimate recombination mechanism is proposed that is involved in the formation of complex T‐DNA inserts as well as in the integration of the T‐DNA in the plant genome.