ISSN:
1617-4623
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The octopine Ti plasmid of Agrobacterium tumefaciens strain Ach5 contains a 13.5 kb TL-region and a 6 kb TR-region which can independently be transferred to plant nuclear DNA. A direct repeat of 25 bp flanks the TL-region, and is related to the direct repeat flanking the nopaline T-region (Zambryski et al. 1982; Yadav et al. 1982). Two right TL-DNA borders, recloned from transformed plant cells, are located in or very near to the right copy of the direct repeat. One left TL-DNA endpoint lies within the left repeat copy, another one is located 57 bp inside of this sequence. These observations are analogous to and generalize the ones made with the nopaline system. A further analogy is the observation that one tumor clone contained a tandem junction of two TL-DNA copies. The junction sequence of 389 bp contains, to the left, a 15 bp sequence representing a direct repeat of a sequence in the right end of TL. The rest of the junction consists mainly of a unit of 40 bp of plant origin directly repeated 6 times. This structure indicates that the generation of the tandem repeat of two TL-DNA copies in this particular tumor line took place during or after the insertion of an original copy in the plant genome.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00330321
Permalink