Mitotic Karyotype of the Primitive Red Alga <i>Cyanidioschyzon merolae</i> 10D

  • Kuroiwa Tsuneyoshi
    Department of Chemical and Biological Science, Japan Women’s University
  • Yagisawa Fumi
    Center for Research Advancement and Collaboration, University of the Ryukyus
  • Fujiwara Takayuki
    Center of Frontier Research, National Institute of Genetics
  • Inui Yayoi
    Research Institute for Science and Technology, Tokyo University of Science
  • M. Matsunaga Tomoko
    Research Institute for Science and Technology, Tokyo University of Science
  • Katoi Shoichi
    Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
  • Matsunaga Sachihiro
    Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science
  • Nagata Noriko
    Department of Chemical and Biological Science, Japan Women’s University
  • Imoto Yuuta
    Department of Cell Biology, Johns Hopkins University School of Medicine
  • Kuroiwa Haruko
    Department of Chemical and Biological Science, Japan Women’s University

Abstract

<p>It is important to understand how a single circular chromosome in the prokaryotic nucleus evolved into multiple linear chromosomes in the eukaryotic nucleus. In most eukaryotic cells that have >∼15 Mbp of genomic DNA, chromosomes remain condensed through all the mitotic phases. Therefore, we observed nuclei of primitive organisms in which linear chromosomes had not been observed previously using conventional methods. Cells of the primitive red alga Cyanidioschyzon merolae, having a genome size of 16.5 Mbp, have been used to study the division of organelles, such as mitochondria, chloroplasts, and peroxisomes. However, morphologically condensed chromosomes have never been observed during mitotic metaphase. Recently, we demonstrated that plastid nuclei are swollen and change from a spherical to a ring shape after being subjected to the glutaraldehyde-fixed-drying method. Using a modified method, we visualized mitotic chromosomes in C. merolae cells. Chromosomal condensation occurred just after the chloroplast division when cells enter metaphase. Thus, chromosomal separation in C. merolae cells likely occurs in a manner similar to that of typical eukaryotic cells. However, mitotic condensed chromosomes were not observed in the primitive green alga Medakamo hakoo, having a genome size of 8 Mbp. Thus, the results support the use of C. merolae as a model for eukaryotic cell analyses.</p>

Journal

  • CYTOLOGIA

    CYTOLOGIA 85 (2), 107-113, 2020-06-25

    Japan Mendel Society, International Society of Cytology

Citations (6)*help

See more

References(22)*help

See more

Related Projects

See more

Details 詳細情報について

Report a problem

Back to top