scholarly journals Trackosome: a computational toolbox to study the spatiotemporal dynamics of centrosomes, nuclear envelope and cellular membrane

2020 ◽  
Author(s):  
Domingos Castro ◽  
Vanessa Nunes ◽  
Joana T. Lima ◽  
Jorge G. Ferreira ◽  
Paulo Aguiar

AbstractDuring the initial stages of mitosis, multiple mechanisms drive centrosome separation and positioning. How they are functionally coordinated to promote centrosome migration to opposite sides of the nucleus remains unclear. Imaging analysis software has been used to quantitatively study centrosome dynamics at this stage. However, available tracking tools are generic and not fine-tuned for the constrains and motion dynamics of centrosome pairs. Such generality limits the tracking performance and may require exhaustive optimization of parameters. Here, we present Trackosome, a freely available open-source computational tool to track the centrosomes and reconstruct the nuclear and cellular membranes, based on volumetric live-imaging data. The toolbox runs in MATLAB and provides a graphical user interface for easy and efficient access to the tracking and analysis algorithms. It outputs key metrics describing the spatiotemporal relations between centrosomes, nucleus and cellular membrane. Trackosome can also be used to measure the dynamic fluctuations of the nuclear envelope. A fine description of these fluctuations is important because they are correlated with the mechanical forces exerted on the nucleus by its adjacent cytoskeletal structures. Unlike previous algorithms based on circular/elliptical approximations of the nucleus, Trackosome measures membrane movement in a model-free condition, making it viable for irregularly shaped nuclei. Using Trackosome, we demonstrate significant correlations between the movements of the two centrosomes, and identify specific modes of oscillation of the nuclear envelope. Overall, Trackosome is a powerful tool to help unravel new elements in the spatiotemporal dynamics of subcellular structures.

2020 ◽  
Vol 133 (24) ◽  
pp. jcs252254
Author(s):  
Domingos Castro ◽  
Vanessa Nunes ◽  
Joana T. Lima ◽  
Jorge G. Ferreira ◽  
Paulo Aguiar

ABSTRACTDuring the initial stages of mitosis, multiple mechanisms drive centrosome separation and positioning. How they are coordinated to promote centrosome migration to opposite sides of the nucleus remains unclear. Here, we present Trackosome, an open-source image analysis software for tracking centrosomes and reconstructing nuclear and cellular membranes, based on volumetric live-imaging data. The toolbox runs in MATLAB and provides a graphical user interface for easy access to the tracking and analysis algorithms. It provides detailed quantification of the spatiotemporal relationships between centrosomes, nuclear envelope and cellular membrane, and can also be used to measure the dynamic fluctuations of the nuclear envelope. These fluctuations are important because they are related to the mechanical forces exerted on the nucleus by its adjacent cytoskeletal structures. Unlike previous algorithms based on circular or elliptical approximations, Trackosome measures membrane movement in a model-free condition, making it viable for irregularly shaped nuclei. Using Trackosome, we demonstrate significant correlations between the movements of the centrosomes, and identify specific oscillation modes of the nuclear envelope. Overall, Trackosome is a powerful tool that can be used to help unravel new elements in the spatiotemporal dynamics of subcellular structures.


2017 ◽  
Vol 30 (2) ◽  
pp. 168-175
Author(s):  
KEISUKE SUGAHARA ◽  
EIKO FUTOO ◽  
HIROKI BESSHO ◽  
RIYO SEKINE ◽  
KEISUKE OHNO ◽  
...  

COMPSTAT ◽  
1996 ◽  
pp. 39-49 ◽  
Author(s):  
William F. Eddy ◽  
Mark Fitzgerald ◽  
Christopher Genovese ◽  
Audris Mockus ◽  
Douglas C. Noll

2018 ◽  
Vol 119 (5) ◽  
pp. 1863-1878 ◽  
Author(s):  
Vahid Rahmati ◽  
Knut Kirmse ◽  
Knut Holthoff ◽  
Stefan J. Kiebel

Calcium imaging provides an indirect observation of the underlying neural dynamics and enables the functional analysis of neuronal populations. However, the recorded fluorescence traces are temporally smeared, thus making the reconstruction of exact spiking activity challenging. Most of the established methods to tackle this issue are limited in dealing with issues such as the variability in the kinetics of fluorescence transients, fast processing of long-term data, high firing rates, and measurement noise. We propose a novel, heuristic reconstruction method to overcome these limitations. By using both synthetic and experimental data, we demonstrate the four main features of this method: 1) it accurately reconstructs both isolated spikes and within-burst spikes, and the spike count per fluorescence transient, from a given noisy fluorescence trace; 2) it performs the reconstruction of a trace extracted from 1,000,000 frames in less than 2 s; 3) it adapts to transients with different rise and decay kinetics or amplitudes, both within and across single neurons; and 4) it has only one key parameter, which we will show can be set in a nearly automatic way to an approximately optimal value. Furthermore, we demonstrate the ability of the method to effectively correct for fast and rather complex, slowly varying drifts as frequently observed in in vivo data. NEW & NOTEWORTHY Reconstruction of spiking activities from calcium imaging data remains challenging. Most of the established reconstruction methods not only have limitations in adapting to systematic variations in the data and fast processing of large amounts of data, but their results also depend on the user’s experience. To overcome these limitations, we present a novel, heuristic model-free-type method that enables an ultra-fast, accurate, near-automatic reconstruction from data recorded under a wide range of experimental conditions.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Stefania Alexandra Iakab ◽  
Lluc Sementé ◽  
María García-Altares ◽  
Xavier Correig ◽  
Pere Ràfols

Abstract Background Multimodal imaging that combines mass spectrometry imaging (MSI) with Raman imaging is a rapidly developing multidisciplinary analytical method used by a growing number of research groups. Computational tools that can visualize and aid the analysis of datasets by both techniques are in demand. Results Raman2imzML was developed as an open-source converter that transforms Raman imaging data into imzML, a standardized common data format created and adopted by the mass spectrometry community. We successfully converted Raman datasets to imzML and visualized Raman images using open-source software designed for MSI applications. Conclusion Raman2imzML enables both MSI and Raman images to be visualized using the same file format and the same software for a straightforward exploratory imaging analysis.


2016 ◽  
Vol 31 (5) ◽  
pp. 1091-1095 ◽  
Author(s):  
Alysen L. Demzik ◽  
Hasham M. Alvi ◽  
Dimitri E. Delagrammaticas ◽  
John M. Martell ◽  
Matthew D. Beal ◽  
...  

2018 ◽  
Vol 24 (3) ◽  
pp. 379-385 ◽  
Author(s):  
X. Wang ◽  
X. Shu ◽  
Z. Li ◽  
W. Huo ◽  
L. Zou ◽  
...  

2003 ◽  
Vol 51 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Christophe F. Chantrain ◽  
Yves A. DeClerck ◽  
Susan Groshen ◽  
George McNamara

Assessment of tissue vascularization using immunohistochemical techniques for microvessel detection has been limited by difficulties in generating reproducible quantitative data. The distinction of individual blood vessels and the selection of microscopic fields to be analyzed remain two factors of subjectivity. In this study, we used imaging analysis software and a high-resolution slide scanner for measurement of CD31-immunostained endothelial area (EA) in whole sections of human neuroblastoma xenograft and murine mammary adenocarcinoma tumors. Imaging analysis software provided objective criteria for analysis of sections of different tumors. The use of the criteria on images of entire tumor section acquired with the slide scanner constituted a rapid method to quantify tumor vascularization. Compared with previously described methods, the “hot spot” and the “random fields” methods, EA measurements obtained with our “whole section scanning” method were more reproducible with 8.6% interobserver disagreement for the “whole section scanning” method vs 42.2% and 39.0% interobserver disagreement for the “hot spot” method and the “random fields,” respectively. Microvessel density was also measured with the whole section scanning method and provided additional data on the distribution and the size of the blood vessels. Therefore, this method constitutes a time efficient and reproducible method for quantification of tumor vascularization.


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