2009/09/16 by Shinji Yoshiyama, Mitsuo Ishigami, Akio Nakamura +1
Engineering · Materials Science · #Diatoms and Algae Research #Polymer Surface Interaction Studies #Slime Mold and Myxomycetes Research
paper · doi:10.1042/cbi20090158
openalex publication_date 2009/09/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
The plasmodium Physarum polycephalum exhibits periodic cycles of cytoplasmic streaming in association with those of contraction and relaxation movement. In the present study, we injected Calcium Green dextran as a fluorescent Ca2+ indicator into the thin-spread living plasmodium. We found changes in the [Ca2+]i (intracellular concentration of Ca2+), which propagated in a wave-like form in its cytoplasm. The Ca2+ waves were also detected when we used Fura dextran which detected [Ca2+]i by the ratio of two wavelengths. We prepared the plasmodial fragment from the thin-spread and found that the cycles of the contraction-relaxation movement was so synchronized that the measurement of its area provided an indication of the movement. We observed that [Ca2+]i also synchronized in the entire fragment and that the relaxation ensued upon the reduction in [Ca2+]i. We suggest that the Ca2+ wave generated periodically is one of the major factors playing a crucial role in the relaxation of P. polycephalum.