Expansion microscopy provides new insights into the cytoskeleton of malaria parasites including the conservation of a conoid

PLoS Biol. 2021 Mar 11;19(3):e3001020. doi: 10.1371/journal.pbio.3001020. eCollection 2021 Mar.


Malaria is caused by unicellular Plasmodium parasites. Plasmodium relies on diverse microtubule cytoskeletal structures for its reproduction, multiplication, and dissemination. Due to the small size of this parasite, its cytoskeleton has been primarily observable by electron microscopy (EM). Here, we demonstrate that the nanoscale cytoskeleton organisation is within reach using ultrastructure expansion microscopy (U-ExM). In developing microgametocytes, U-ExM allows monitoring the dynamic assembly of axonemes and concomitant tubulin polyglutamylation in whole cells. In the invasive merozoite and ookinete forms, U-ExM unveils the diversity across Plasmodium stages and species of the subpellicular microtubule arrays that confer cell rigidity. In ookinetes, we additionally identify an apical tubulin ring (ATR) that colocalises with markers of the conoid in related apicomplexan parasites. This tubulin-containing structure was presumed to be lost in Plasmodium despite its crucial role in motility and invasion in other apicomplexans. Here, U-ExM reveals that a divergent and considerably reduced form of the conoid is actually conserved in Plasmodium species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytoskeleton / metabolism
  • Cytoskeleton / ultrastructure*
  • Malaria / metabolism
  • Malaria / parasitology
  • Microscopy, Electron / methods
  • Microtubules / metabolism
  • Microtubules / ultrastructure*
  • Parasites
  • Plasmodium / metabolism
  • Plasmodium / pathogenicity
  • Plasmodium / ultrastructure
  • Toxoplasma / metabolism
  • Toxoplasma / pathogenicity
  • Toxoplasma / ultrastructure*
  • Tubulin


  • Tubulin

Grant support

This work was supported by the Swiss National Science Foundation (SNSF) PP00P3_187198 attributed to PG, BSSGI0_155852 and 31003A_179321 to MB, and by the European Research Council ERC ACCENT StG 715289 attributed to PG. MB is an INSERM investigator. MB and PG are EMBO young investigators. EB is supported by an EMBO long-term fellowship (ALTF-284-2019). BM is funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program under Grant agreement no. 695596. VH is funded by the European Research Council ERC ACCENT StG 715289 and PG by the Swiss National Science Foundation (SNSF) PP00P3_187198. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.