Ultrastructural observation of natural field phytoplankton cells by using rapid freezing and freeze substitution

• Kimura Kei

  National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency

• Tomaru Yuji

  National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency

• Nagasaki Keizo

  National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency

Abstract

Transmission electron microscopy (TEM) is a basic technique used to study the ultrastructures of phytoplankton. However, the use of chemical fixation to prepare phytoplankton samples for TEM is laborious and time-consuming. Furthermore, chemical fixation often causes artificial structural changes (artifacts) in phytoplankton cells. In this study, we induced and optimized a rapid freezing and freeze substitution (RFS) method, accompanied by a filter dehydration system, to prepare TEM samples of marine microalgae, including Heterosigma akashiwo, Chattonella antiqua (Raphidophyceae), Heterocapsa circularisquama (Dinophyceae), Chaetoceros tenuissimus (Bacillariophyceae), and Teleaulax amphioxeia (Cryptophyceae). The whole procedure was much more efficient than the traditional method. In addition, the fine structure of each microalgal cell was well preserved. For example, the fine structures of the nuclear membrane, nuclear pores, and several vesicles were clearly observed, which were comparatively difficult to observe using the chemical fixation method. In addition, this new technique was applicable to the natural blooming cells of H. akashiwo, and high-resolution ultrastructural images were successfully observed. This is the first report on the application of the modified-RFS method for natural phytoplankton assemblages. This method can be used for diverse phytoplankters in natural waters, and the high-quality observations are expected to provide useful information toward understanding phytoplankter physiology and ecology.

Journal

• Plankton and Benthos Research

  Plankton and Benthos Research 7 (3), 126-134, 2012

  The Plankton Society of Japan, The Japanese Association of Benthology

Keywords

• electron microscopy
• modified-RFS method
• phytoplankton
• rapid freezing and freeze substitution

Details

• CRID: 1390001205265814272
• NII Article ID: 10030870818
• NII Book ID: AA12130745
• DOI: 10.3800/pbr.7.126
• ISSN: 1882627X
• ISSN: 18808247
• NDL BIB ID: 023934484
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I023934484
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed