scholarly journals GraviKit: an easy-to-implement microscope add-on for observation of gravitation dependent processes

2021 ◽  
Author(s):  
Christian Feldhaus ◽  
Martina Kolb ◽  
Michelle Kueppers ◽  
Steffen Hardy ◽  
Ralph Palmisano
Keyword(s):  
Light Microscopy ◽  
Optical Axis ◽  
Technical Skills ◽  
Environmental Cues ◽  
Developmental Processes ◽  
Imaging Device ◽  
Imaging Experiment ◽  
Living Organisms ◽  
Dependent Processes

One of the most important environmental cues for living organisms is gravity and many developmental processes depend on it. However, when it comes to light microscopy, a majority of studies on these processes work with their objects of interest placed perpendicular to their natural orientation. One reason for that is probably that light microscopes with the required horizontal beampath are either costly or require advanced technical skills. To circumvent these obstacles and make imaging of gravity-dependent processes with a horizontal beampath possible for any lab we developed GraviKit. It converts a standard inverted research microscope into an imaging device with a horizontal beampath with a stage that rotates the sample around the optical axis. Like this, the direction of gravity can be freely chosen during an imaging experiment. The system is easy to implement and suitable for multi-user environments.

scholarly journals Shedding light on biology of bacterial cells

2016 ◽  
Vol 371 (1707) ◽  
pp. 20150499 ◽  
Author(s):  
Johannes P. Schneider ◽  
Marek Basler
Keyword(s):  
Light Microscopy ◽  
Live Cell Imaging ◽  
Spatial Organization ◽  
Cell Imaging ◽  
Live Cell ◽  
Bacterial Cells ◽  
Resolution Limit ◽  
Detection Techniques ◽  
Living Organisms ◽  
Cellular Components

To understand basic principles of living organisms one has to know many different properties of all cellular components, their mutual interactions but also their amounts and spatial organization. Live-cell imaging is one possible approach to obtain such data. To get multiple snapshots of a cellular process, the imaging approach has to be gentle enough to not disrupt basic functions of the cell but also have high temporal and spatial resolution to detect and describe the changes. Light microscopy has become a method of choice and since its early development over 300 years ago revolutionized our understanding of living organisms. As most cellular components are indistinguishable from the rest of the cellular contents, the second revolution came from a discovery of specific labelling techniques, such as fusions to fluorescent proteins that allowed specific tracking of a component of interest. Currently, several different tags can be tracked independently and this allows us to simultaneously monitor the dynamics of several cellular components and from the correlation of their dynamics to infer their respective functions. It is, therefore, not surprising that live-cell fluorescence microscopy significantly advanced our understanding of basic cellular processes. Current cameras are fast enough to detect changes with millisecond time resolution and are sensitive enough to detect even a few photons per pixel. Together with constant improvement of properties of fluorescent tags, it is now possible to track single molecules in living cells over an extended period of time with a great temporal resolution. The parallel development of new illumination and detection techniques allowed breaking the diffraction barrier and thus further pushed the resolution limit of light microscopy. In this review, we would like to cover recent advances in live-cell imaging technology relevant to bacterial cells and provide a few examples of research that has been possible due to imaging. This article is part of the themed issue ‘The new bacteriology’.

Rudiment resorption as a response to starvation during larval development in the sea urchin Strongylocentrotus droebachiensis

2018 ◽  
Vol 96 (10) ◽  
pp. 1178-1185
Author(s):  
A. Singh ◽  
L. Pinto ◽  
C. Martin ◽  
N. Rutherford ◽  
A. Ragunathan ◽  
...  
Keyword(s):  
Larval Development ◽  
Sea Urchin ◽  
Strongylocentrotus Droebachiensis ◽  
Phenotypic Change ◽  
Environmental Cues ◽  
Phenotypic Flexibility ◽  
Window Of Opportunity ◽  
Developmental Processes ◽  
First Time ◽  
Developmental Window

Phenotypic flexibility (reversible phenotypic change) enables organisms to couple internal, ontogenetic responses with external, environmental cues. Phenotypic flexibility also provides organisms with the capacity to buffer stereotypical internal, developmental processes from unpredictable external, ecological events. Echinoids exhibit dramatic phenotypic flexibility in response to variation in exogenous nutrient supplies. The extent to which echinoids display this flexibility has been explored incompletely and research hitherto has been conducted predominantly on larval structures and morphologies. We investigated experimentally the extent to which the primordial juvenile, the developing rudiment, can exhibit the first phase in phenotypic flexibility among individuals. We report for the first time on rudiment regression and complete resorption as a response to starvation during larval development in the sea urchin Strongylocentrotus droebachiensis (O.F. Müller, 1776) and identify a developmental “window of opportunity” within which this can occur. Based on our observations and previous suggestions, we speculate that sea urchin rudiments might provide means of buffering development during unfavorable conditions.

RNA switches regulate initiation of translation in bacteria

2008 ◽  
Vol 389 (5) ◽  
Author(s):  
Stefano Marzi ◽  
Pierre Fechter ◽  
Clément Chevalier ◽  
Pascale Romby ◽  
Thomas Geissmann
Keyword(s):  
Conformational Changes ◽  
Regulatory Proteins ◽  
Environmental Cues ◽  
Structural Elements ◽  
Direct Effects ◽  
Regulate Gene Expression ◽  
Initiation Of Translation ◽  
Rna Switches ◽  
Non Coding Rnas ◽  
Living Organisms

AbstractA large variety of RNA-based mechanisms have been uncovered in all living organisms to regulate gene expression in response to internal and external changes, and to rapidly adapt cell growth in response to these signals. In bacteria, structural elements in the 5′ leader regions of mRNAs have direct effects on translation initiation of the downstream coding sequences. The docking and unfolding of these mRNAs on the 30S subunit are critical steps in the initiation process directly modulating and timing translation. Structural elements can also undergo conformational changes in response to environmental cues (i.e., temperature sensors) or upon binding of a variety oftrans-acting factors, such as metabolites, non-coding RNAs or regulatory proteins. These RNA switches can temporally regulate translation, leading either to repression or to activation of protein synthesis.

Creating colour-contrast in light microscopy of living organisms

1998 ◽  
Vol 32 (1) ◽  
pp. 29-33 ◽  
Author(s):  
R. H. Newton ◽  
J. P. Haffegee ◽  
M. W. Ho
Keyword(s):  
Light Microscopy ◽  
Colour Contrast ◽  
Living Organisms

scholarly journals A Study of the Temperature Dependence of Bienzyme Systems and Enzymatic Chains

2007 ◽  
Vol 8 (2) ◽  
pp. 93-112 ◽  
Author(s):  
N. V. Kotov ◽  
R. E. Baker ◽  
D. A. Dawidov ◽  
K. V. Platov ◽  
N. V. Valeyev ◽  
...  
Keyword(s):  
Temperature Compensation ◽  
Apparent Temperature ◽  
Strong Variation ◽  
Temperature Dependent ◽  
Controlled Processes ◽  
Reversible Reactions ◽  
Similar Temperature ◽  
Living Organisms ◽  
The Relationship ◽  
Dependent Processes

It is known that most enzyme-facilitated reactions are highly temperature dependent processes. In general, the temperature coefficient,Q10, of a simple reaction reaches 2.0–3.0. Nevertheless, some enzyme-controlled processes have much lowerQ10(about 1.0), which implies that the process is almost temperature independent, even if individual reactions involved in the process are themselves highly temperature dependent. In this work, we investigate a possible mechanism for this apparent temperature compensation: simple mathematical models are used to study how varying types of enzyme reactions are affected by temperature. We show that some bienzyme-controlled processes may be almost temperature independent if the modules involved in the reaction have similar temperature dependencies, even if individually, these modules are strongly temperature dependent. Further, we show that in non-reversible enzyme chains the stationary concentrations of metabolites are dependent only on the relationship between the temperature dependencies of the first and last modules, whilst in reversible reactions, there is a dependence on every module. Our findings suggest a mechanism by which the metabolic processes taking place within living organisms may be regulated, despite strong variation in temperature.

scholarly journals An Electron Optical Achromat

1997 ◽  
Vol 5 (6) ◽  
pp. 3-5
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Light Microscopy ◽  
Optical Axis ◽  
Spherical Aberration ◽  
Chromatic Aberration ◽  
Chromatic Aberrations

Spherical and chromatic aberrations have been the bane of optical lenses ever since they were first ground from a piece of glass. As light travels through a convex (converging) lens, the rays at the center of the optical axis are refracted (bent) less than the peripheral rays, so that the central rays are focused behind the peripheral rays. This is the essence of spherical aberration. Light of differing wavelengths (colors) interact differently with the lens so that longer wavelengths (red) are focused behind shorter wavelengths (blue). This is chromatic aberration. In the early days of light microscopy, these two inherent flaws seriously limited the quality of images.

scholarly journals A beginner’s guide to rigor and reproducibility in fluorescence imaging experiments

2018 ◽  
Vol 29 (13) ◽  
pp. 1519-1525 ◽  
Author(s):  
Jen-Yi Lee ◽  
Maiko Kitaoka
Keyword(s):  
Light Microscopy ◽  
Fluorescence Imaging ◽  
Cancer Metastasis ◽  
Fluorescent Proteins ◽  
Biological Mechanisms ◽  
Imaging Experiment ◽  
Fluorescence Light Microscopy ◽  
Fluorescence Light ◽  
Experimental Approaches ◽  
Insight Into

Fluorescence light microscopy is an indispensable approach for the investigation of cell biological mechanisms. With the development of cutting-edge tools such as genetically encoded fluorescent proteins and superresolution methods, light microscopy is more powerful than ever at providing insight into a broad range of phenomena, from bacterial fission to cancer metastasis. However, as with all experimental approaches, care must be taken to ensure reliable and reproducible data collection, analysis, and reporting. Each step of every imaging experiment, from design to execution to communication to data management, should be critically assessed for bias, rigor, and reproducibility. This Perspective provides a basic “best practices” guide for designing and executing fluorescence imaging experiments, with the goal of introducing researchers to concepts that will help empower them to acquire images with rigor.

Radiocarbon Map of a Bomb-Peak Labeled Human Eye

Radiocarbon ◽  
2019 ◽  
Vol 62 (1) ◽  
pp. 189-196
Author(s):  
Laszlo Rinyu ◽  
Robert Janovics ◽  
Mihaly Molnar ◽  
Zoltan Kisvarday ◽  
Adam Kemeny-Beke
Keyword(s):  
Anatomical Location ◽  
Living Matter ◽  
Metabolic Processes ◽  
Developmental Processes ◽  
Human Eye ◽  
Living Organisms ◽  
Inner Parts ◽  
Different Tissues

ABSTRACTThe 14C/12C ratio of living organisms is largely determined by the 14C/12C ratio of consumed diet as well as by the atmospheric 14C concentration together with the body’s metabolic processes. The measured 14C content of living matter compared to the atmospheric radiocarbon level can provide invaluable information about developmental processes. Our aim was to determine the 14C content of ten different tissues of the human eye using the 14C bomb-pulse dating signature. The 14C content of the atmosphere, so called 14C “bomb-pulse” has labeled humanity offering an opportunity to determine these special formation, turnover and substitution courses in biology. The results allowed us to construct a 14C map of the bomb-peak labeled human eye. According to the anatomical location of the tissues, an unexpected picture emerged as in moving from the outer parts towards the inner parts of the eye, the 14C content of each tissue decreased. The data presented here are compatible with the view that the oldest parts of the eye are the sclera, the limbus and the cornea, in this order, and moving further inside, the youngest tissue of the eye is the retina.

scholarly journals Different ways to obtain similar results: the development of the corolla and epipetaly in Rubieae (Rubioideae, Rubiaceae)

2020 ◽  
Vol 153 (3) ◽  
pp. 466-486
Author(s):  
Alexander Vrijdaghs ◽  
Erik Smets ◽  
Petra De Block
Keyword(s):  
Light Microscopy ◽  
19Th Century ◽  
Floral Development ◽  
Corolla Tube ◽  
Sensu Stricto ◽  
Herbaceous Plants ◽  
Floral Ontogeny ◽  
Developmental Processes ◽  
Postgenital Fusion ◽  
Scanning Electron

Background and aims – Rubieae is a tribe in the subfamily Rubioideae characterised by herbaceous plants with verticillate leaves and flowers with a rudimentary or absent calyx and a short, cup-shaped corolla. This is in contrast to the flowers of most other Rubiaceae, in which the tubular corolla is longer than the corolla lobes. Also, the description by Payer, a French 19th century pioneer of floral ontogenetic research, of the floral development in Asperula, Galium, and Rubia deviates from recent insights about the development of tubular corollas, which are based on investigations of flowers of tropical Rubiaceae. Tubular corollas are currently considered as resulting from the development of underlying annular intercalary meristems, whereas Payer explained the tubular corollas in the three taxa by postgenital fusion. We therefore tested both hypotheses in six Rubieae genera, including the three taxa studied by Payer.Methods – Floral ontogeny of ten species in six Rubieae genera based on scanning electron (SEM) and light microscopy (LM). Conclusions – Our results suggest that, in all species studied, the mature phenotype of the corolla as well as the epipetaly of the stamens is caused by a combination of three developmental processes (the development of a stamen-corolla tube, the development of a corolla tube sensu stricto, and postgenital fusion), and the relative moment of activation of each of these processes during floral development (plastochron variation or heterochrony).

scholarly journals Photosynthesis-assisted remodeling of three-dimensional printed structures

2021 ◽  
Vol 118 (3) ◽  
pp. e2016524118
Author(s):  
Kunhao Yu ◽  
Zhangzhengrong Feng ◽  
Haixu Du ◽  
An Xin ◽  
Kyung Hoon Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Three Dimensional ◽  
Environmental Cues ◽  
Engineering Structures ◽  
3D Print ◽  
Lightweight Structures ◽  
Smart Composites ◽  
Material Fatigue ◽  
Cell Structures ◽  
Living Organisms

The mechanical properties of engineering structures continuously weaken during service life because of material fatigue or degradation. By contrast, living organisms are able to strengthen their mechanical properties by regenerating parts of their structures. For example, plants strengthen their cell structures by transforming photosynthesis-produced glucose into stiff polysaccharides. In this work, we realize hybrid materials that use photosynthesis of embedded chloroplasts to remodel their microstructures. These materials can be used to three-dimensionally (3D)-print functional structures, which are endowed with matrix-strengthening and crack healing when exposed to white light. The mechanism relies on a 3D-printable polymer that allows for an additional cross-linking reaction with photosynthesis-produced glucose in the material bulk or on the interface. The remodeling behavior can be suspended by freezing chloroplasts, regulated by mechanical preloads, and reversed by environmental cues. This work opens the door for the design of hybrid synthetic-living materials, for applications such as smart composites, lightweight structures, and soft robotics.

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