Three-dimensional reconstructions of portions the Golgi complex from cryofixed, freeze-substituted normal rat kidney cells have been made by dual-axis, high-voltage EM tomography at approximately 7-nm resolution. The reconstruction shown here ( 1 x 4 microm3) contains two stacks seven cisternae separated a noncompact region across which bridges connect some equivalent levels, but none nonequivalent levels. rest is filled with both vesicles and polymorphic membranous elements. All are...

The three dimensional organization of microtubules in mitotic spindles the yeast Saccharomyces cerevisiae has been determined by computer-aided reconstruction from electron micrographs serially cross-sectioned spindles. Fifteen ranging length 0.6-9.4 microns have analyzed. Ordered microtubule packing is absent up to 0.8 micron, but total number sufficient allow one per kinetochore with a few additional that may form an interpolar spindle. An obvious bundle about eight was found 1.3-1.6 long,...

Journal Article SerialEM: A Program for Automated Tilt Series Acquisition on Tecnai Microscopes Using Prediction of Specimen Position Get access David N Mastronarde Boulder Laboratory Three Dimensional Electron Microscopy Cells, Dept. Molecular, Cellular, and Developmental Biology, University Colorado, Boulder, CO 80309 Search other works by this author on: Oxford Academic Google Scholar Microanalysis, Volume 9, Issue S02, 1 August 2003, Pages 1182–1183,...

The endoplasmic reticulum (ER) network is extremely dynamic in animal cells, yet little known about the mechanism and function of its movements. most common ER dynamic, termed sliding, involves tubule extension along stable microtubules (MTs). In this study, we show that sliding occurs on nocodazole-resistant MTs are posttranslationally modified by acetylation. We demonstrate high MT curvature a good indicator acetylation live cells predominantly these curved, acetylated MTs. Furthermore,...

The trans Golgi network (TGN) of plant cells sorts and packages products into secretory (SV) clathrin‐coated (CCV) vesicles. We have analyzed TGN cisternae in Arabidopsis root meristem by cell fractionation electron microscopy/tomography to establish reliable criteria for identifying cells, define their functional attributes. Transformation a cisterna Golgi‐associated begins with cisternal peeling, the formation SV buds outside plane 30–35% reduction membrane area. Free compartments are...

The positional relationships among all of the visible organelles in a densely packed region cytoplasm from an insulin secreting, cultured mammalian cell have been analyzed three dimensions (3-D) at ≈6 nm resolution. Part fast frozen/freeze-substituted HIT-T15 that included large portion Golgi ribbon was reconstructed 3-D by electron tomography. volume (3.1 × 3.2 1.2 μm 3 ) allowed sites interaction between organelles, and microtubules organellar membranes, to be accurately defined...

Spindle microtubules (MTs) in PtK1 cells, fixed at stages from metaphase to telophase, have been reconstructed using serial sections, electron microscopy, and computer image processing. We studied the class of MTs that form an interdigitating system connecting two spindle poles (interpolar or ipMTs) their relationship attach kinetochores (kMTs). Viewed cross section, ipMTs cluster with antiparallel near neighbors throughout mitosis; this bundling becomes much more pronounced as anaphase...

1. The shared inputs to cat retinal ganglion cells have been investigated by studying correlations in the maintained firing of neighboring cells. one cell was recorded from its axon optic tract, while that a simultaneously with second electrode retina. were X- or Y-type and viewed uniform screen having luminance 10 cd/m2. 2. Ganglion overlapping receptive-field centers showed two basic forms correlated firing: if they had same center sign (both on-center both off-center), then tended fire at...

The retinal inputs to cells in the cat's lateral geniculate nucleus (LGN) were directly recorded study basis for properties of two classes LGN X-cells: Xs (single) and XL (lagged). presence excitatory or inhibitory input an cell from a particular simultaneously ganglion was assessed with cross-correlograms during unstimulated activity. Because neighboring do not fire independently, features retinogeniculate correlogram can arise ways that must be distinguished by direct effect on cell,...

The number of nuclear pore complexes (NPCs) in individual nuclei the yeast Saccharomyces cerevisiae was determined by computer-aided reconstruction entire from electron micrographs serially sectioned cells. Nuclei 32 haploid cells at various points cell cycle were modeled and found to contain between 65 182 NPCs. Morphological markers, such as shape shape, used determine stage being examined. NPC correlated with reveal that NPCs increases steadily, beginning G1-phase, suggesting assembly...

The three-dimensional architecture of syncytial-type cell plates in the endosperm Arabidopsis has been analyzed at approximately 6-nm resolution by means dual-axis high-voltage electron tomography high-pressure frozen/freeze-substituted samples. Mini-phragmoplasts consisting microtubule clusters assemble between sister and nonsister nuclei. Most Golgi-derived vesicles appear connected to these microtubules two molecules that resemble kinesin-like motor proteins. These fuse with each other...

We have analyzed the fine structure of 10 chromosomal fibers from mitotic spindles PtK1 cells in metaphase and anaphase, using electron microscopy serial thin sections computer image processing to follow trajectories component microtubules (MTs) three dimensions. Most kinetochore MTs ran their vicinity pole, retaining a clustered arrangement over entire length. This MT bundle was invaded by large numbers other that were not associated with kinetochores. The invading frequently came close...

We have used computer averaging of electron micrographs from longitudinal and cross-sections wild-type mutant axonemes to determine the arrangement inner dynein arms in Chlamydomonas reinhardtii. Based on biochemical morphological data, previously been described as consisting three distinct subspecies, I1, I2, I3. Our averages revealed 10 distinguishable lobes density per 96-nm repeating unit row arms. These occurred predominantly but not exclusively two parallel rows. analyzed strains that...