Alteration in cytosine methylation at the 5'-CCGG sites within and immediately flanking the Dart -related TEs in three rice- Zizania introgressants, detected by methylation-sensitive Southern blot analysis. (a) Restriction maps of enzymes BamHI and HpaII/MspI for Dart-related TEs. The restriction sites for the enzyme (BamHI) used to delineate Dart-related TEs and the pair of isoschizomers, HpaII/MspI (H/M), within the elements are indicated. Fragments to be used as probes that are respectively specific to the 5'-, 3'- and body-regions are denoted by solid bars. (b) Hybridization of each of the three probes (uppermost: the body-region, middle: the 5'-region, lowermost: the 3'-region) to a blot carrying single- or double-enzyme digested genomic DNA of the introgressants and their parental lines, rice (cv. Matsumae) and Z. latifolia. The enzymes used were indicated on the top of the blot: BamHI (B), HpaII (H) and MspI (M). The altered bands indicative of methylation alterations in the introgressant(s) are arrowed.