https://bio3d.colorado.edu/SerialEM/serialEMJSB.pdf

Automated electron microscope tomography using robust prediction of specimen movements.

EMAN2: an extensible image processing suite for electron microscopy.

Mitochondrial structure and distribution are regulated by division and fusion events. Mitochondrial division is regulated by Dnm1/Drp1, a dynamin-related protein that forms helices around mitochondria to mediate fission. Little is known about what determines sites of mitochondrial fission within the mitochondrial network. The endoplasmic reticulum (ER) and mitochondria exhibit tightly coupled dynamics and have extensive contacts. We tested whether ER plays a role in mitochondrial division. We found that mitochondrial division occurred at positions where ER tubules contacted mitochondria and mediated constriction before Drp1 recruitment. Thus, ER tubules may play an active role in defining the position of mitochondrial division sites.

/pdf/er-tubules-mark-sites-of-mitochondrial-division-502a8m340x.pdf

ER Tubules Mark Sites of Mitochondrial Division

Dual-axis tomography: an approach with alignment methods that preserve resolution.

Autophagy is a bulk degradation process in eukaryotic cells and has fundamental roles in cellular homeostasis.The origin and source of autophagosomal membranes are long-standing questions in the field. Using electron microscopy, we show that, in mammalian culture cells, the endoplasmic reticulum (ER) associates with early autophagic structures called isolation membranes (IMs). Overexpression of an Atg4B mutant, which causes defects in autophagosome formation, induces the accumulation of ER-IM complexes. Electron tomography revealed that the ER-IM complex appears as a subdomain of the ER that formed a cradle encircling the IM, and showed that both ER and isolation membranes are interconnected.

James R. Kremer

Papers

Computer Visualization of Three-Dimensional Image Data Using IMOD

High Voltage Cryomicroscopy of Human Blood Platelets

New image-modeling software used for 3-D analysis of biological EM data on silicon graphics computers

Analysis of photographic emulsions for High-Voltage Electron Microscopy

Three-dimensional reconstruction of the golgi complex and trans-golgi network: A HVEM tomographic study