Intercellular transport across pit-connections in the filamentous red alga Griffithsia monilis

  • Kim, Gwang Hoon (Department of Biological Sciences, Kongju National University) ;
  • Nagasato, Chikako (Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University) ;
  • Kwak, Minseok (Department of Taxonomy and Systematics, National Marine Biodiversity Institute of Korea) ;
  • Lee, Ji Woong (Department of Biological Sciences, Kongju National University) ;
  • Hong, Chan Young (Department of Biological Sciences, Kongju National University) ;
  • Klochkova, Tatyana A. (Kamchatka State Technical University) ;
  • Motomura, Taizo (Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University)
  • Received : 2021.11.17
  • Accepted : 2022.02.16
  • Published : 2022.03.15


Intercellular nutrient and signal transduction are essential to sustaining multicellular organisms and maximizing the benefits of multicellularity. It has long been believed that red algal intercellular transport of macromolecules is prevented by the protein-rich pit plug within pit-connections, the only physical connection between cells. Fluorescein isothiocyanate-dextran and recombinant green fluorescence protein (rGFP) of various molecular sizes were injected into vegetative cells of Griffithsia monilis using a micromanipulator, and intercellular transport of the fluorescent probes was examined. Pit-connections were found to provide intercellular transport of tracers at rates comparable to plasmodesmata in other organisms. The time necessary for the transport to an adjacent cell was dependent on the molecular size and the direction of the transport. Fluorescent dextran of 3 kDa was transported to adjacent cells in 1-2 h after injection and migrated to all cells of the filament within 24 h, but fluorescent dextran of 10-20 kDa took 24 h to transfer to neighboring cells. The migration occurred faster towards adjacent reproductive cells and to apical cells than basally. Fluorescent tracers above 40 kDa and rGFP was not transported to neighboring cells, but accumulated near the pit plug. Our results suggest that pit-connections are conduit for macromolecules between neighboring cells and that these size-specific conduits allow intercellular communication between the vegetative cells of red algae.



GHK thanks to Hokkaido University for supporting his stay in Muroran Marine Station as a visiting professor. This research was supported by Marine Biotechnology Program of the Korea Institute of Marine Science and Technology Promotion (KIMST) funded by the Ministry of Oceans and Fisheries (MOF) (No.20170431) and by National Marine Biodiversity Institute of Korea (2021M01100).


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