[Table of Contents]

Plasma and Fusion Research

Volume 2, S1007 (2007)

Regular Articles

Observation of in vivo DNA in Ice Embedded whole Cyanobacterial Cells by Hilbert Differential Contrast Transmission Electron Microscopy (HDC-TEM)
Yasuko KANEKO, Koji NITTA1) and Kuniaki NAGAYAMA1)
Biology Section in the Faculty of Education, and Graduate School of Science and Engineering, Saitama University,Saitama 338-8570 Japan
1)
Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
(Received 4 December 2006 / Accepted 16 February 2007 / Published 20 November 2007)

Abstract

HDC-TEM has opened a way to visualize the ultrastructure of ice embedded whole cells. The extraordinary advantage of this technique is that it exhibits structures close to the living state while retaining all the in vivo molecular constituents undisturbed. We attempted to identify in vivo DNA by incorporation of BrdU, which conferred electron density to newly synthesized DNA in ice embedded cyanobacterial cells. Localization of Br in the electron dense area in the identical cell was investigated by electron spectroscopic imaging (ESI). Br was also appeared to be associated with polyphosphate bodies, which would indicate a close relationship between newly synthesized DNA and polyphosphate bodies. While ESI indicates the DNA localization, high resolution HDC-TEM reveals the fine fibrous structures in situ. The combination of ESI with HDC-TEM will be extremely useful to study the in vivo dynamics of DNA synthesis, and its structural and conformational changes close to the living state at high resolution.

Keywords

phase contrast electron microscope, cyanobacteria, in vivo DNA, rapid freezing, electron spectroscopic imaging

DOI: 10.1585/pfr.2.S1007

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This paper may be cited as follows:

Yasuko KANEKO, Koji NITTA and Kuniaki NAGAYAMA, Plasma Fusion Res. 2, S1007 (2007).