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bioRxiv · 10.1101/329300

Bidirectional intraflagellar transport is restricted to only two microtubule doublets in the trypanosome flagellum

Bertiaux, E.·Mallet, A.·Fort, C.·Blisnick, T.·Bonnefoy, S.·Jung, J.·Lemos, M.·Marco, S.·Vaughan, S.·Trepout, S.·Tinevez, J.-Y.·Bastin, P.
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Abstract

Intraflagellar transport (IFT) is the rapid bidirectional movement of large protein complexes driven by kinesin and dynein motors along microtubule doublets of cilia and flagella. Here we used a combination of high-resolution electron and light microscopy to investigate how and where these IFT trains move within the flagellum of the protist Trypanosoma brucei. Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) analysis of trypanosomes showed that trains are found almost exclusively along two sets of doublets (3-4 and 7-8) and distribute in two categories according to their length. High-resolution live imaging of cells expressing mNeonGreen::IFT81 or GFP::IFT52 revealed for the first time IFT trafficking on two parallel lines within the flagellum. Anterograde and retrograde IFT occur on each of these lines. At the distal end, a large individual anterograde IFT train is converted in several smaller retrograde trains in the space of 3-4 seconds while remaining on the same side of the axoneme.

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Bertiaux, E., Mallet, A., Fort, C., Blisnick, T., Bonnefoy, S., Jung, J., Lemos, M., Marco, S., Vaughan, S., Trepout, S., Tinevez, J.-Y., Bastin, P.. 2018-05-23. Bidirectional intraflagellar transport is restricted to only two microtubule doublets in the trypanosome flagellum. https://doi.org/10.1101/329300

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