tailieunhanh - Báo cáo khoa học: DNA adenine methylation changes dramatically during establishment of symbiosis

The DNA adenine methylation status on specific 5¢-GANTC-3¢ sites and its change during the establishment of plant–microbe interactions was demonstrated in several species ofa-proteobacteria. Restriction landmark genome scanning (RLGS), which is a high-resolution two dimensional DNA electrophoresis method, was used to monitor the genomewide change in methylation. | ỊFEBS Journal DNA adenine methylation changes dramatically during establishment of symbiosis Hiroyuki Ichida1 2 Tomoki Matsuyama3 Tomoko Abe2 and Takato Koba1 1 Graduate Schoolof Science and Technology Chiba University Matsudo Japan 2 Accelerator Application Research Group Nishina Center for Accelerator-Based Science RIKEN Hirosawa Wako Saitama Japan 3 Cellular Biochemistry Laboratory Discovery Research Institute RIKEN Hirosawa Wako Saitama Japan Keywords cell cycle-regulated methyltransferase DNA adenine methylation in silico restriction landmark genome scanning plant-microbe interactions specifically unmethylated region Correspondence H. Ichida Accelerator Application Research Group Nishina Center for Accelerator-Based Science RIKEN 2-1 Hirosawa Wako Saitama 351-0198 Japan Fax 81 48 4624674 Tel 81 48 4621111 Ext. 5432 E-mail ichida@ Received 31 October 2006 revised 7 December 2006 accepted 11 December 2006 The DNA adenine methylation status on specific 5 -GANTC-3 sites and its change during the establishment of plant-microbe interactions was demonstrated in several species of a-proteobacteria. Restriction landmark genome scanning RLGS which is a high-resolution two dimensional DNA electrophoresis method was used to monitor the genomewide change in methylation. In the case of Mesorhizobium loti MAFF303099 real RLGS images obtained with the restriction enzyme MboI which digests at GATC sites almost perfectly matched the virtual RLGS images generated based on genome sequences. However only a few spots were observed when the restriction enzyme Hinfl was used suggesting that most GANTC Hinfl sites were tightly methylated and specific sites were unmethylated. DNA gel blot analysis with the cloned specifically unmethylated regions SUMs showed that some SUMs were methylated differentially in bacter-oids compared to free-living bacteria. SUMs have also been identified in other symbiotic and parasitic bacteria. These results suggest that DNA adenine methylation may