title: Methylation of the T-DNA in Agrobacterium tumefaciens and in several crown gall tumors.
abstract: Methylation of the T-DNA in Agrobacterium tumefaciens and in four octopine-type (A6S/2, E9, 15955/1, 15955/01) and one nopaline-type (HT37#15) crown gall tumors was investigated using the isoschizomeric restriction endonucleases Msp I and Hpa II. T-DNA in the octopine-type Ti-plasmid pTiB6(806) was not methylated at the sequence 5'CCGG3' in Agrobacterium. With two possible exceptions, neither was the T-DNA of the nopaline-type Ti-plasmid pTiT37 methylated in the bacterium. In all tumor lines investigated, at least one copy of the T-DNA was not methylated. DNA methylation was not detected in the lines A6S/2, 15955/1, HT37#15, and the TL region of E9. DNA methylation of some copies of TR in the E9 tumor line, and possibly in the 15955/01 line, was detected. The methylation of some copies of TR in the E9 line may indicate that not all copies of TR are transcribed in this tumor.
mesh_terms: D002460:Cell Line; D004247:DNA / Q000235:genetics*; D004262:DNA Restriction Enzymes; D008745:Methylation; D010941:Plant Tumors; D010957:Plasmids; D012231:Rhizobium / Q000235:genetics*; D013045:Species Specificity
chemical_list: D004247:DNA; D004262:DNA Restriction Enzymes