Fig. 2

Structure of the autonomous chromosome 4 of S. vulgaris KRA. Southern blot hybridization probed with 626 bp long sequence specific to chromosome 4. Total DNAs were extracted from leaf (L) or flower bud (B) tissues of two female (F) and two hermaphroditic (H) plants. DNAs were either digested with the restriction enzyme BglII recognizing a single site in chromosome 4 (right), treated with nickase Nb.BssSI capable of introducing one single-strand cut in chromosome 4 (middle), or not digested at all (left). Molecular weight standards were loaded on both sides of the 1% agarose gel. Black arrows point to the bands corresponding to linear monomer (2.56 kb) or dimer (5.12 kb) of chromosome 4. White arrows point to the supercoiled monomer or open (relaxed) circle monomer or oligomers