scholarly journals Actin Filament Bundles in Drosophila Wing Hairs: Hairs and Bristles Use Different Strategies for Assembly

2005 ◽  
Vol 16 (8) ◽  
pp. 3620-3631 ◽  
Author(s):  
Gregory M. Guild ◽  
Patricia S. Connelly ◽  
Linda Ruggiero ◽  
Kelly A. Vranich ◽  
Lewis G. Tilney

Actin filament bundles can shape cellular extensions into dramatically different forms. We examined cytoskeleton formation during wing hair morphogenesis using both confocal and electron microscopy. Hairs elongate with linear kinetics (∼1 μm/h) over the course of ∼18 h. The resulting structure is vividly asymmetric and shaped like a rose thorn—elongated in the distal direction, curved in two dimensions with an oval base and a round tip. High-resolution analysis shows that the cytoskeleton forms from microvilli-like pimples that project actin filaments into the cytoplasm. These filaments become cross-linked into bundles by the sequential use of three cross-bridges: villin, forked and fascin. Genetic loss of each cross-bridge affects cell shape. Filament bundles associate together, with no lateral membrane attachments, into a cone of overlapping bundles that matures into an oval base by the asymmetric addition of bundles on the distal side. In contrast, the long bristle cell extension is supported by equally long (up to 400 μm) filament bundles assembled together by end-to-end grafting of shorter modules. Thus, bristle and hair cells use microvilli and cross-bridges to generate the common raw material of actin filament bundles but employ different strategies to assemble these into vastly different shapes.

1994 ◽  
Vol 144 ◽  
pp. 593-596
Author(s):  
O. Bouchard ◽  
S. Koutchmy ◽  
L. November ◽  
J.-C. Vial ◽  
J. B. Zirker

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.


2021 ◽  
Vol 13 (3) ◽  
pp. 1093
Author(s):  
Yunlong Zhao ◽  
Geng Kong ◽  
Chin Hao Chong ◽  
Linwei Ma ◽  
Zheng Li ◽  
...  

Controlling energy consumption to reduce greenhouse gas emissions has become a global consensus in response to the challenge of climate change. Most studies have focused on energy consumption control in a single region; however, high-resolution analysis of energy consumption and personalized energy policy-making, for multiple regions with differentiated development, have become a complicated challenge. Using the logarithmic mean Divisia index I (LMDI) decomposition method based on energy allocation analysis (EAA), this paper aims to establish a standard paradigm for a high-resolution analysis of multi-regional energy consumption and provide suggestions for energy policy-making, taking 29 provinces of China as the sample. The process involved three steps: (1) determination of regional priorities of energy consumption control by EAA, (2) revealing regional disparity among the driving forces of energy consumption growth by LMDI, and (3) deriving policy implications by comparing the obtained results with existing policies. The results indicated that 29 provinces can be divided into four groups, with different priorities of energy consumption control according to the patterns of coal flows. Most provinces have increasing levels of energy consumption, driven by increasing per capita GDP and improving living standards, while its growth is restrained by decreasing end-use energy intensity, improving energy supply efficiency, and optimization of industrial structures. However, some provinces are not following these trends to the same degree. This indicates that policy-makers must pay more attention to the different driving mechanisms of energy consumption growth among provinces.


2002 ◽  
Vol 70 (5) ◽  
pp. 1197-1214 ◽  
Author(s):  
Fulvio Cruciani ◽  
Piero Santolamazza ◽  
Peidong Shen ◽  
Vincent Macaulay ◽  
Pedro Moral ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aleksandar Antanasijevic ◽  
Leigh M. Sewall ◽  
Christopher A. Cottrell ◽  
Diane G. Carnathan ◽  
Luis E. Jimenez ◽  
...  

AbstractEngineered ectodomain trimer immunogens based on BG505 envelope glycoprotein are widely utilized as components of HIV vaccine development platforms. In this study, we used rhesus macaques to evaluate the immunogenicity of several stabilized BG505 SOSIP constructs both as free trimers and presented on a nanoparticle. We applied a cryoEM-based method for high-resolution mapping of polyclonal antibody responses elicited in immunized animals (cryoEMPEM). Mutational analysis coupled with neutralization assays were used to probe the neutralization potential at each epitope. We demonstrate that cryoEMPEM data can be used for rapid, high-resolution analysis of polyclonal antibody responses without the need for monoclonal antibody isolation. This approach allowed to resolve structurally distinct classes of antibodies that bind overlapping sites. In addition to comprehensive mapping of commonly targeted neutralizing and non-neutralizing epitopes in BG505 SOSIP immunogens, our analysis revealed that epitopes comprising engineered stabilizing mutations and of partially occupied glycosylation sites can be immunogenic.


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