Figure 8

DNA methylation on CcAdoMetS gene. (A) Restriction enzyme cleavage of C. cohnii DNA. (B) Panel 1, Ethidium bromide stained agarose gels and panel 2, southern blotting showing restriction patterns of C. cohnii genomic DNA digested with isoshizomeric enzymes HpaII and MspI recognizing CCGG sequences. Lane Uc was uncut DNA. Lane H and M showed the pattern of restriction after DNA was treated with HpaII and MspI respectively. Absence of fragments smaller than around 2 kbp was observed in Lane H (Arrow). (C) The presence of interference within digestion was tested by treating with bacteriophage λDNA restriction enzyme with HpaII and MspI restriction enzymes. Lane λH and λM showed the restriction pattern of HpaII and MspI respectively. Lane λUc was uncut control λDNA. (D) Southern blot analysis of C. cohnii DNA after treated with DNA methylation inhibitors 5-azacytidine and L-ethionine. Ethidium bromide stained agarose gels and southern blotting showing the restriction pattern of DNA by HpaII (H) and MspI (M) without any treatment; after treating with 200 μM 5Aza and after treating with 1.2 mM L-Eth. Presence of fragments smaller than around 2 kbp was observed in HpaII digested DNA after treated with 5Aza and L-Eth (Arrow).