PT  - JOURNAL ARTICLE
AU  - Eloïse Bertiaux
AU  - Adeline Mallet
AU  - Cécile Fort
AU  - Thierry Blisnick
AU  - Serge Bonnefoy
AU  - Jamin Jung
AU  - Moara Lemos
AU  - Sergio Marco
AU  - Sue Vaughan
AU  - Sylvain Trépout
AU  - Jean-Yves Tinevez
AU  - Philippe Bastin
TI  - Bidirectional intraflagellar transport is restricted to only two microtubule doublets in the trypanosome flagellum
AID  - 10.1101/329300
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 329300
4099  - http://biorxiv.org/content/early/2018/05/23/329300.short
4100  - http://biorxiv.org/content/early/2018/05/23/329300.full
AB  - 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 doublets 4 and 7 and that trains 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 distinct tracks within the flagellum and that anterograde and retrograde IFT takes place on each of these tracks. 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 track.FIB-SEMFocused Ion Beam Scanning Electron MicroscopyIFAimmunofluorescence assayIFTintraflagellar transportPFRparaflagellar rodTEMtransmission electron microscopy