High resolution imaging of the ER-Golgi interface through FIB-SEM
ER exit sites (ERES) of the collagen-producing larval fat body imaged through focused ion beam scanning electron microscopy (FIB-SEM). In each ERES-Golgi unit, the Golgi apparatus (pink) is wrapped by a cup of fenestrated ER sheets (green). Ribosome-devoid ERES regions (grey) are found on the concave side of the cup. Between ERES and Golgi, there are numerous small vesicles (yellow) consistent in size with regular COPII and COPI vesicles. No evidence of larger “megacarrier” vesicles is observed. However, tubular continuities (blue) are seen that directly connect ERES and Golgi. This characterization of ERES-Golgi units provides key insights for understanding secretory transport of large protein cargos at the ER-Golgi interface.
Video Credit: Ke Yang
Yang K, Liu M, Feng Z, Rojas M, Zhou L, Ke H, Pastor-Pareja JC.
ER exit sites in Drosophila display abundant ER-Golgi vesicles and pearled tubes but no megacarriers.
Cell Rep. 2021 Sep 14;36(11):109707
Centrosome Biogenesis under Sub-Diffraction Resolution
For stimula00ted emission depletion (STED) microscopy, Drosophila cultured cell lines constitutively expressing GFP-fused protein were fixed and immunostained with GFP-booster Atto488 (green) and antibody against the N-terminus of Asl (red). For ultra-expansion microscopy (U-ExM), Drosophila cultured cell lines constitutively expressing GFP-fused protein were embedded in polyacrylamide hydrogel. After digestion, expansion, labelling with antibodies against GFP (green) and the N-terminus of Asl (Red), gels were visualized via three dimensional structured illumination microscopy (3D-SIM). Micrograms demonstrated the radial distributions of multiple toroid-shaped proteins. Further analyses revealed relative distribution of pairwise proteins along angular axis. The diameter of each centriolar protein matches its assembly order during centrosome duplication that concerts with cell-division cycle.
Image Credit: Yuan Tian, Yuxuan Yan, Jingyan Fu
Tian Y, Wei C, He J, Yan Y, Pang N, Fang X, Liang X, Fu J.
Superresolution characterization of core centriole architecture.
J Cell Biol. 2021 Apr 5;220(4)