title: In situ analysis of the higher-order genome structure in a single Escherichia coli cell.
abstract: We developed a novel method for the in situ analysis of the higher-order structure of an individual genome from a single Escherichia coli cell using laser tweezers. Initially, condensed DNA was stably grasped by a laser without any chemical modification and without physical attachment to an artificial object such as micro-plastic beads. Under optical transport, the trapped genome gradually unfolded in solution due to viscous friction. Interestingly, the nucleoid DNA from a log-phase cell is almost fully elongated, whereas in the stationary phase, unfolding of the nucleoid is characterized by step-wise elongation of 1.7-5.1 microm, corresponding to a size of 5-15 kbp, and a few tightly packed domains remain along the DNA chain. This suggests the coexistence of tightly packed and swollen domains in the genome in the stationary phase.
authors: Laboratory of Plasma Membrane and Nuclear Signaling, Graduate School of Biostudies, Kyoto University, Kyoto, Japan.
authors: Eri
authors: E
authors: Shindo
authors: Koji
authors: K
authors: Kubo
authors: Ryosuke L
authors: RL
authors: Ohniwa
authors: Kunio
authors: K
authors: Takeyasu
authors: Kenichi
authors: K
authors: Yoshikawa
mesh_terms: D001692:Biological Transport; D002021:Buffers; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000166:cytology* / Q000235:genetics* / Q000648:ultrastructure; D005821:Genetic Techniques; D016680:Genome, Bacterial / Q000235:genetics*; D007211:Indoles; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D052898:Optical Tweezers
chemical_list: D002021:Buffers; D004269:DNA, Bacterial; D007211:Indoles; C007293:DAPI