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Neděla V, Tihlaříková E, Cápal P, Doležel J. Advanced environmental scanning electron microscopy reveals natural surface nano-morphology of condensed mitotic chromosomes in their native state. Sci Rep 2024; 14:12998. [PMID: 38844535 PMCID: PMC11156959 DOI: 10.1038/s41598-024-63515-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/29/2024] [Indexed: 06/09/2024] Open
Abstract
The challenge of in-situ handling and high-resolution low-dose imaging of intact, sensitive and wet samples in their native state at nanometer scale, including live samples is met by Advanced Environmental Scanning Electron Microscopy (A-ESEM). This new generation of ESEM utilises machine learning-based optimization of thermodynamic conditions with respect to sample specifics to employ a low temperature method and an ionization secondary electron detector with an electrostatic separator. A modified electron microscope was used, equipped with temperature, humidity and gas pressure sensors for in-situ and real-time monitoring of the sample. A transparent ultra-thin film of ionic liquid is used to increase thermal and electrical conductivity of the samples and to minimize sample damage by free radicals. To validate the power of the new method, we analyze condensed mitotic metaphase chromosomes to reveal new structural features of their perichromosomal layer, and the organization of chromatin fibers, not observed before by any microscopic technique. The ability to resolve nano-structural details of chromosomes using A-ESEM is validated by measuring gold nanoparticles with achievable resolution in the lower nanometre units.
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Affiliation(s)
- Vilém Neděla
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, Brno, 612 00, Czech Republic.
| | - Eva Tihlaříková
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, Brno, 612 00, Czech Republic
| | - Petr Cápal
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, Olomouc, 772 00, Czech Republic
| | - Jaroslav Doležel
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of Plant Structural and Functional Genomics, Šlechtitelů 31, Olomouc, 772 00, Czech Republic
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2
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Decellularized Pancreatic Tail as Matrix for Pancreatic Islet Transplantation into the Greater Omentum in Rats. J Funct Biomater 2022; 13:jfb13040171. [PMID: 36278640 PMCID: PMC9589982 DOI: 10.3390/jfb13040171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/29/2022] Open
Abstract
Infusing pancreatic islets into the portal vein currently represents the preferred approach for islet transplantation, despite considerable loss of islet mass almost immediately after implantation. Therefore, approaches that obviate direct intravascular placement are urgently needed. A promising candidate for extrahepatic placement is the omentum. We aimed to develop an extracellular matrix skeleton from the native pancreas that could provide a microenvironment for islet survival in an omental flap. To that end, we compared different decellularization approaches, including perfusion through the pancreatic duct, gastric artery, portal vein, and a novel method through the splenic vein. Decellularized skeletons were compared for size, residual DNA content, protein composition, histology, electron microscopy, and MR imaging after repopulation with isolated islets. Compared to the other approaches, pancreatic perfusion via the splenic vein provided smaller extracellular matrix skeletons, which facilitated transplantation into the omentum, without compromising other requirements, such as the complete depletion of cellular components and the preservation of pancreatic extracellular proteins. Repeated MR imaging of iron-oxide-labeled pancreatic islets showed that islets maintained their position in vivo for 49 days. Advanced environmental scanning electron microscopy demonstrated that islets remained integrated with the pancreatic skeleton. This novel approach represents a proof-of-concept for long-term transplantation experiments.
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Bačovský V, Čegan R, Tihlaříková E, Neděla V, Hudzieczek V, Smrža L, Janíček T, Beneš V, Hobza R. Chemical genetics in Silene latifolia elucidate regulatory pathways involved in gynoecium development. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2354-2368. [PMID: 35045170 DOI: 10.1093/jxb/erab538] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
Dioecious plants possess diverse sex determination systems and unique mechanisms of reproductive organ development; however, little is known about how sex-linked genes shape the expression of regulatory cascades that lead to developmental differences between sexes. In Silene latifolia, a dioecious plant with stable dimorphism in floral traits, early experiments suggested that female-regulator genes act on the factors that determine the boundaries of the flower whorls. To identify these regulators, we sequenced the transcriptome of male flowers with fully developed gynoecia, induced by rapid demethylation in the parental generation. Eight candidates were found to have a positive role in gynoecium promotion, floral organ size, and whorl boundary, and affect the expression of class B MADS-box flower genes. To complement our transcriptome analysis, we closely examined the floral organs in their native state using field emission environmental scanning electron microscopy, and examined the differences between females and androhermaphrodites in their placenta and ovule organization. Our results reveal the regulatory pathways potentially involved in sex-specific flower development in the classical model of dioecy, S. latifolia. These pathways include previously hypothesized and unknown female-regulator genes that act on the factors that determine the flower boundaries, and a negative regulator of anther development, SUPERMAN-like (SlSUP).
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Affiliation(s)
- Václav Bačovský
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Radim Čegan
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Eva Tihlaříková
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 612 64 Brno, Czech Republic
| | - Vilém Neděla
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 612 64 Brno, Czech Republic
| | - Vojtěch Hudzieczek
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Lubomír Smrža
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Tomáš Janíček
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Vladimír Beneš
- EMBL Genomics Core Facility, EMBL Heidelberg, Meyerhofstraße 1, D-69117 Heidelberg, Germany
| | - Roman Hobza
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 65 Brno, Czech Republic
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Lee H, Partanen M, Lee M, Jeong S, Lee HJ, Kim K, Ryu W, Dholakia K, Oh K. A laser-driven optical atomizer: photothermal generation and transport of zeptoliter-droplets along a carbon nanotube deposited hollow optical fiber. NANOSCALE 2022; 14:5138-5146. [PMID: 35302135 DOI: 10.1039/d1nr06211e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
From mechanical syringes to electric field-assisted injection devices, precise control of liquid droplet generation has been sought after, and the present state-of-the-art technologies have provided droplets ranging from nanoliter to subpicoliter volume sizes. In this study, we present a new laser-driven method to generate liquid droplets with a zeptoliter volume, breaking the fundamental limits of previous studies. We guided an infrared laser beam through a hollow optical fiber (HOF) with a ring core whose end facet was coated with single-walled carbon nanotubes. The laser light was absorbed by this nanotube film and efficiently generated a highly localized microring heat source. This evaporated the liquid inside the HOF, which rapidly recondensed into zeptoliter droplets in the surrounding air at room temperature. We spectroscopically confirmed the chemical structures of the liquid precursor maintained in the droplets by atomizing dye-dissolved glycerol. Moreover, we explain the fundamental physical principles as well as functionalities of the optical atomizer and perform a detailed characterization of the droplets. Our approach has strong prospects for nanoscale delivery of biochemical substances in minuscule zeptoliter volumes.
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Affiliation(s)
- Hyeonwoo Lee
- Photonic Device Physics Laboratory, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
| | - Mikko Partanen
- Photonic Device Physics Laboratory, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
- Photonics Group, Department of Electronics and Nanoengineering, Aalto University, P.O. Box 13500, 00076 Aalto, Finland
| | - Mingyu Lee
- Photonic Device Physics Laboratory, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
| | - Sunghoon Jeong
- Photonic Device Physics Laboratory, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
| | - Hyeung Joo Lee
- Photonic Device Physics Laboratory, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
| | - Kwanpyo Kim
- Department of Physics, Yonsei University, Seoul 03722, Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea
| | - Wonhyoung Ryu
- Biomedical and Energy System Laboratory, Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
| | - Kishan Dholakia
- Photonic Device Physics Laboratory, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
- SUPA, School of Physics and Astronomy, University of St Andrews, KY16 9SS, UK.
| | - Kyunghwan Oh
- Photonic Device Physics Laboratory, Department of Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
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Závacká K, Neděla V, Tihlaříková E, Šabacká P, Maxa J, Heger D. ESEM Methodology for the Study of Ice Samples at Environmentally Relevant Subzero Temperatures: "Subzero ESEM". MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 28:196-209. [PMID: 34937589 DOI: 10.1017/s1431927621013854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Frozen aqueous solutions are an important subject of study in numerous scientific branches including the pharmaceutical and food industry, atmospheric chemistry, biology, and medicine. Here, we present an advanced environmental scanning electron microscope methodology for research of ice samples at environmentally relevant subzero temperatures, thus under conditions in which it is extremely challenging to maintain the thermodynamic equilibrium of the specimen. The methodology opens possibilities to observe intact ice samples at close to natural conditions. Based on the results of ANSYS software simulations of the surface temperature of a frozen sample, and knowledge of the partial pressure of water vapor in the gas mixture near the sample, we monitored static ice samples over several minutes. We also discuss possible artifacts that can arise from unwanted surface ice formation on, or ice sublimation from, the sample, as a consequence of shifting conditions away from thermodynamic equilibrium in the specimen chamber. To demonstrate the applicability of the methodology, we characterized how the true morphology of ice spheres containing salt changed upon aging and the morphology of ice spheres containing bovine serum albumin. After combining static observations with the dynamic process of ice sublimation from the sample, we can attain images with nanometer resolution.
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Affiliation(s)
- Kamila Závacká
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 61264Brno, Czech Republic
| | - Vilém Neděla
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 61264Brno, Czech Republic
| | - Eva Tihlaříková
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 61264Brno, Czech Republic
| | - Pavla Šabacká
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 61264Brno, Czech Republic
| | - Jiří Maxa
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 61264Brno, Czech Republic
| | - Dominik Heger
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 62500Brno, Czech Republic
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Šabacká P, Neděla V, Maxa J, Bayer R. Application of Prandtl's Theory in the Design of an Experimental Chamber for Static Pressure Measurements. SENSORS 2021; 21:s21206849. [PMID: 34696062 PMCID: PMC8538980 DOI: 10.3390/s21206849] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/16/2022]
Abstract
Pumping in vacuum chambers is part of the field of environmental electron microscopy. These chambers are separated from each other by a small-diameter aperture that creates a critical flow in the supersonic flow regime. The distribution of pressure and shock waves in the path of the primary electron beam passing through the differentially pumped chamber has a large influence on the quality of the resulting microscope image. As part of this research, an experimental chamber was constructed to map supersonic flow at low pressures. The shape of this chamber was designed using mathematical–physical analyses, which served not only as a basis for the design of its geometry, but especially for the correct choice of absolute and differential pressure sensors with respect to the cryogenic temperature generated in the supersonic flow. The mathematical and physical analyses presented here map the nature of the supersonic flow with large gradients of state variables at low pressures at the continuum mechanics boundary near the region of free molecule motion in which the Environmental Electron Microscope and its differentially pumped chamber operate, which has a significant impact on the resulting sharpness of the final image obtained by the microscope. The results of this work map the flow in and behind the Laval nozzle in the experimental chamber and are the initial basis that enabled the optimization of the design of the chamber based on Prandtl’s theory for the possibility of fitting it with pressure probes in such a way that they can map the flow in and behind the Laval nozzle.
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Affiliation(s)
- Pavla Šabacká
- Institute of Scientific Instruments of the CAS, 61264 Brno, Czech Republic; (P.Š.); (V.N.)
- Department of Electrical and Electronic Technology, Brno University of Technology, 61100 Brno, Czech Republic;
| | - Vilém Neděla
- Institute of Scientific Instruments of the CAS, 61264 Brno, Czech Republic; (P.Š.); (V.N.)
| | - Jiří Maxa
- Institute of Scientific Instruments of the CAS, 61264 Brno, Czech Republic; (P.Š.); (V.N.)
- Department of Electrical and Electronic Technology, Brno University of Technology, 61100 Brno, Czech Republic;
- Correspondence:
| | - Robert Bayer
- Department of Electrical and Electronic Technology, Brno University of Technology, 61100 Brno, Czech Republic;
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Stelate A, Tihlaříková E, Schwarzerová K, Neděla V, Petrášek J. Correlative Light-Environmental Scanning Electron Microscopy of Plasma Membrane Efflux Carriers of Plant Hormone Auxin. Biomolecules 2021; 11:1407. [PMID: 34680040 PMCID: PMC8533460 DOI: 10.3390/biom11101407] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022] Open
Abstract
Fluorescence light microscopy provided convincing evidence for the domain organization of plant plasma membrane (PM) proteins. Both peripheral and integral PM proteins show an inhomogeneous distribution within the PM. However, the size of PM nanodomains and protein clusters is too small to accurately determine their dimensions and nano-organization using routine confocal fluorescence microscopy and super-resolution methods. To overcome this limitation, we have developed a novel correlative light electron microscopy method (CLEM) using total internal reflection fluorescence microscopy (TIRFM) and advanced environmental scanning electron microscopy (A-ESEM). Using this technique, we determined the number of auxin efflux carriers from the PINFORMED (PIN) family (NtPIN3b-GFP) within PM nanodomains of tobacco cell PM ghosts. Protoplasts were attached to coverslips and immunostained with anti-GFP primary antibody and secondary antibody conjugated to fluorochrome and gold nanoparticles. After imaging the nanodomains within the PM with TIRFM, the samples were imaged with A-ESEM without further processing, and quantification of the average number of molecules within the nanodomain was performed. Without requiring any post-fixation and coating procedures, this method allows to study details of the organization of auxin carriers and other plant PM proteins.
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Affiliation(s)
- Ayoub Stelate
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague 2, Czech Republic; (A.S.); (K.S.)
| | - Eva Tihlaříková
- Institute of Scientific Instruments, Academy of Sciences of the Czech Republic, Královopolská 147, 612 64 Brno, Czech Republic; (E.T.); (V.N.)
| | - Kateřina Schwarzerová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague 2, Czech Republic; (A.S.); (K.S.)
| | - Vilém Neděla
- Institute of Scientific Instruments, Academy of Sciences of the Czech Republic, Královopolská 147, 612 64 Brno, Czech Republic; (E.T.); (V.N.)
| | - Jan Petrášek
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague 2, Czech Republic; (A.S.); (K.S.)
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Neděla V, Tihlaříková E, Maxa J, Imrichová K, Bučko M, Gemeiner P. Simulation-based optimisation of thermodynamic conditions in the ESEM for dynamical in-situ study of spherical polyelectrolyte complex particles in their native state. Ultramicroscopy 2020; 211:112954. [PMID: 32018072 DOI: 10.1016/j.ultramic.2020.112954] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/23/2020] [Accepted: 01/26/2020] [Indexed: 11/18/2022]
Abstract
We present a complex analysis and optimisation of dynamic conditions in the environmental scanning electron microscope (ESEM) to allow in-situ observation of extremely delicate wet bio-polymeric spherical particles in their native state. According to the results of gas flow and heat transfer simulations, we were able to develop an improved procedure leading to thermodynamic equilibrium between the sample and chamber environment. To quantify and hence minimise the extent of any sample deformation during specimen chamber pumping, a strength-stress analysis is used. Monte Carlo simulations of beam-gas, -water, and -sample interactions describe beam scattering, absorbed energy, interaction volume and the emission of signal electrons in the ESEM. Finally, we discuss sample damage as a result of drying and the production of beam-induced free radicals. Based on all experimental and simulation results we introduce a Delicate Sample Observation Strategy for the ESEM. We show how this strategy can be applied to the characterization of polyelectrolyte complex spherical particles containing immobilized recombinant cells E. coli overexpressing cyclohexanone monooxygenase, used as a model biocatalyst. We present the first native-state electron microscopy images of the viscous core of a halved polyelectrolyte complex capsule containing living cells.
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Affiliation(s)
- Vilém Neděla
- Environmental electron microscopy group, Institute of Scientific Instruments of ASCR, Královopolská 147, 61264 Brno, Czech Republic.
| | - Eva Tihlaříková
- Environmental electron microscopy group, Institute of Scientific Instruments of ASCR, Královopolská 147, 61264 Brno, Czech Republic
| | - Jiří Maxa
- Environmental electron microscopy group, Institute of Scientific Instruments of ASCR, Královopolská 147, 61264 Brno, Czech Republic
| | - Kamila Imrichová
- Environmental electron microscopy group, Institute of Scientific Instruments of ASCR, Královopolská 147, 61264 Brno, Czech Republic
| | - Marek Bučko
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, 84538 Bratislava, Slovakia
| | - Peter Gemeiner
- Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, 84538 Bratislava, Slovakia
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Tihlaříková E, Neděla V, Đorđević B. In-situ preparation of plant samples in ESEM for energy dispersive x-ray microanalysis and repetitive observation in SEM and ESEM. Sci Rep 2019; 9:2300. [PMID: 30783188 PMCID: PMC6381206 DOI: 10.1038/s41598-019-38835-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 01/07/2019] [Indexed: 11/25/2022] Open
Abstract
The Extended Low Temperature Method (ELTM) for the in-situ preparation of plant samples in an environmental scanning electron microscope enables carrying out repetitive topographical and material analysis at a higher resolution in the vacuum conditions of a scanning electron microscope or in the low gas pressure conditions of an environmental scanning electron microscope. The method does not require any chemical intervention and is thus suitable for imaging delicate structures rarely observable with common treatment methods. The method enables both sample stabilization as close to their native state as possible, as well as the transfer of the same sample from a low vacuum to an atmospheric condition for sample storage or later study. It is impossible for wet samples in the environmental scanning electron microscope. Our studies illustrate the high applicability of the ELTM for different types of plant tissue, from imaging of plant waxes at higher resolution, the morphological study of highly susceptible early somatic embryos to the elemental microanalysis of root cells. The method established here provides a very fast, universal and inexpensive solution for plant sample treatment usable in a commercial environmental scanning electron microscope equipped with a cooling Peltier stage.
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Affiliation(s)
- Eva Tihlaříková
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, 612 00, Czech Republic.
| | - Vilém Neděla
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, 612 00, Czech Republic
| | - Biljana Đorđević
- Department of Plant Biology, Mendel University in Brno, Brno, 613 00, Czech Republic
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Eliášová K, Vondráková Z, Gemperlová L, Neděla V, Runštuk J, Fischerová L, Malbeck J, Trávníčková A, Cvikrová M, Vágner M. The Response of Picea abies Somatic Embryos to UV-B Radiation Depends on the Phase of Maturation. FRONTIERS IN PLANT SCIENCE 2018; 9:1736. [PMID: 30538715 PMCID: PMC6277568 DOI: 10.3389/fpls.2018.01736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
Ultraviolet-B (UV-B) radiation is a key environmental signal which initiates diverse responses that affect the metabolism, development, and viability of plants. In keeping with our previous studies, we concentrated primarily on how UV-B radiation affects Norway spruce [Picea abies (L.) Karst.] somatic embryo maturation and how phenolics and polyamines (PAs) are linked to the defense response invoked by UV-B irradiation. We treated clusters of Norway spruce embryogenic culture (EC) with UV-B during the five stages of embryo maturation (early, cylindrical, precotyledonary, cotyledonary, and mature embryos). For the first time, we take an advantage of the unique environmental scanning electron microscope AQUASEM II to characterize somatic embryos in their native state. The severity of the irradiation effect on embryonal cell viability was shown to be dependent on the intensity of radiation as well as the stage of embryo development, and might be related to the formation of protoderm. The response of early embryos was characterized by an increase in malondialdehyde (MDA), a marked decrease in PA contents and a decline in phenolics. The reduced ability to activate the defense system seems to be responsible not only for the severe cell damage and decrease in viability but also for the inhibition of embryo development. The significant reduction in spermidine (Spd), which has been reported to be crucial for the somatic embryo development of several coniferous species, may be causally linked to the limited development of embryos. The pronounced decrease in cell wall-bound ferulic acid might correspond to failure of somatic embryos to reach more advanced stages of development. Embryos at later stages of development showed stress defense responses that were more efficient against UV-B exposure.
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Affiliation(s)
- Kateřina Eliášová
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Zuzana Vondráková
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Lenka Gemperlová
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Vilém Neděla
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czechia
| | - Jiří Runštuk
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czechia
| | - Lucie Fischerová
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Jiří Malbeck
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Alena Trávníčková
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Milena Cvikrová
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Martin Vágner
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
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Michaloudi E, Papakostas S, Stamou G, Neděla V, Tihlaříková E, Zhang W, Declerck SAJ. Reverse taxonomy applied to the Brachionus calyciflorus cryptic species complex: Morphometric analysis confirms species delimitations revealed by molecular phylogenetic analysis and allows the (re)description of four species. PLoS One 2018; 13:e0203168. [PMID: 30235243 PMCID: PMC6147415 DOI: 10.1371/journal.pone.0203168] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/14/2018] [Indexed: 12/13/2022] Open
Abstract
The discovery and exploration of cryptic species have been profoundly expedited thanks to developments in molecular biology and phylogenetics. In this study, we apply a reverse taxonomy approach to the Brachionus calyciflorus species complex, a commonly studied freshwater monogonont rotifer. By combining phylogenetic, morphometric and morphological analyses, we confirm the existence of four cryptic species that have been recently suggested by a molecular study. Based on these results and according to an exhaustive review of the taxonomic literature, we name each of these four species and provide their taxonomic description alongside a diagnostic key.
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Affiliation(s)
- Evangelia Michaloudi
- Department of Zoology, School of Biology, Aristotle University of Thessaloniki, Τhessaloniki, Greece
| | - Spiros Papakostas
- Division of Genetics and Physiology, Department of Biology, University of Turku, Turku, Finland
| | - Georgia Stamou
- Department of Zoology, School of Biology, Aristotle University of Thessaloniki, Τhessaloniki, Greece
| | - Vilém Neděla
- Institute of Scientific Instruments, Academy Of Sciences of the Czech Republic, Brno, Czech Republic
| | - Eva Tihlaříková
- Institute of Scientific Instruments, Academy Of Sciences of the Czech Republic, Brno, Czech Republic
| | - Wei Zhang
- Netherlands Institute of Ecology, Department of Aquatic Ecology, Wageningen, The Netherlands
| | - Steven A. J. Declerck
- Netherlands Institute of Ecology, Department of Aquatic Ecology, Wageningen, The Netherlands
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Đorđević B, Neděla V, Tihlaříková E, Trojan V, Havel L. Effects of copper and arsenic stress on the development of Norway spruce somatic embryos and their visualization with the environmental scanning electron microscope. N Biotechnol 2018; 48:35-43. [PMID: 29782934 DOI: 10.1016/j.nbt.2018.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 11/17/2022]
Abstract
Somatic embryogenesis is an important biotechnological technique which can be used in studies associated with environmental stress. Four embryogenic cell lines of Norway spruce were grown on media enriched with copper and arsenic in concentration ranges 50-500 μM and 10-50 μM, respectively. The effects were observed during subsequent stages of somatic embryogenesis, the characteristics evaluated being proliferation potential, average number of somatic embryos obtained per g/fresh weight, morphology of developed somatic embryos, metal uptake, and microanalysis of macro- and micronutrients uptake. Copper and arsenic at higher concentrations significantly reduced the growth of early somatic embryos. In almost all treatments, the cell line V-1-3 showed the best performance compared with the other lines tested. Environmental scanning electron microscopy was used to visualize and identify morphological abnormalities in the development of somatic embryos. Abnormalities observed were classified into several categories: meristemless somatic embryos, somatic embryos with disrupted meristem, reduced number of cotyledons, single cotyledon and fused cotyledons. With the application of a low temperature method for the environmental scanning electron microscope, samples were stabilized and whole meristems could be investigated in their native state. As far as we are aware, this is the first report of the effect of copper and arsenic during the process of somatic embryogenesis and the first to evaluate the content of macro and micronutrients uptake in Norway spruce.
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Affiliation(s)
- Biljana Đorđević
- Department of Plant Biology, Mendel University in Brno, Zemědělská 1, Brno 613 00, Czech Republic.
| | - Vilém Neděla
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, Brno 612 64, Czech Republic
| | - Eva Tihlaříková
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, Brno 612 64, Czech Republic
| | - Václav Trojan
- Department of Plant Biology, Mendel University in Brno, Zemědělská 1, Brno 613 00, Czech Republic
| | - Ladislav Havel
- Department of Plant Biology, Mendel University in Brno, Zemědělská 1, Brno 613 00, Czech Republic
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13
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High-efficiency detector of secondary and backscattered electrons for low-dose imaging in the ESEM. Ultramicroscopy 2018; 184:1-11. [DOI: 10.1016/j.ultramic.2017.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 08/02/2017] [Accepted: 08/10/2017] [Indexed: 11/21/2022]
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14
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Effect of the preparation of lime putties on their properties. Sci Rep 2017; 7:17260. [PMID: 29222495 PMCID: PMC5722907 DOI: 10.1038/s41598-017-17527-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/27/2017] [Indexed: 11/08/2022] Open
Abstract
In the study of lime as the basic component of historical mortars and plasters, four lime putties prepared from various kinds of lime of various granulometry and by various ways of preparation were evaluated. The rheological properties and micro-morphologic changes, growing of calcite crystals, and rate of carbonation were monitored. The lime putty prepared from lump lime achieves the best rheological properties, yield stress 214.7 Pa and plastic viscosity 2.6 Pa·s. The suitability of this lime putty was checked by testing the development of calcium hydroxide and calcite crystals using scanning electron microscopy and environmental scanning electron microscopy. The disordered crystals of calcium hydroxide exhibit better carbonation resulting in the large crystals of calcite; therefore, the mortar prepared from the lump lime has the highest flexural strength and compressive strength 0.8/2.5 MPa, its carbonation is the fastest and exhibits the longest durability. Also, thanks to the micro-morphological characterization of samples in their native state by means of environmental scanning electron microscopy, the new way of lime putty preparation by mixing was proven. The preparation consists in the mechanical crash of the lime particles immediately after hydration. This enables the properties of putty prepared from lump lime to be nearly reached.
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Slówko W, Wiatrowski A, Krysztof M. Detection of secondary and backscattered electrons for 3D imaging with multi-detector method in VP/ESEM. Micron 2017; 104:45-60. [PMID: 29080547 DOI: 10.1016/j.micron.2017.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/07/2017] [Accepted: 10/08/2017] [Indexed: 10/18/2022]
Abstract
The paper considers some major problems of adapting the multi-detector method for three-dimensional (3D) imaging of wet bio-medical samples in Variable Pressure/Environmental Scanning Electron Microscope (VP/ESEM). The described method pertains to "single-view techniques", which to create the 3D surface model utilise a sequence of 2D SEM images captured from a single view point (along the electron beam axis) but illuminated from four directions. The basis of the method and requirements resulting from them are given for the detector systems of secondary (SE) and backscattered electrons (BSE), as well as designs of the systems which could work in variable conditions. The problems of SE detection with application of the Pressure Limiting Aperture (PLA) as the signal collector are discussed with respect to secondary electron backscattering by a gaseous environment. However, the authors' attention is turned mainly to the directional BSE detection, realized in two ways. The high take off angle BSE were captured through PLA with use of the quadruple semiconductor detector placed inside the intermediate chamber, while BSE starting at lower angles were detected by the four-folded ionization device working in the sample chamber environment. The latter relied on a conversion of highly energetic BSE into low energetic SE generated on walls and a gaseous environment of the deep discharge gap oriented along the BSE velocity direction. The converted BSE signal was amplified in an ionising avalanche developed in the electric field arranged transversally to the gap. The detector system operation is illustrated with numerous computer simulations and examples of experiments and 3D images. The latter were conducted in a JSM 840 microscope with its combined detector-vacuum equipment which could extend capabilities of this high vacuum instrument toward elevated pressures (over 1kPa) and environmental conditions.
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Affiliation(s)
- Witold Slówko
- Wroclaw University of Science and Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw, Poland.
| | - Artur Wiatrowski
- Wroclaw University of Science and Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw, Poland
| | - Michał Krysztof
- Wroclaw University of Science and Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw, Poland
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16
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Progress in emerging techniques for characterization of immobilized viable whole-cell biocatalysts. CHEMICAL PAPERS 2017. [DOI: 10.1007/s11696-017-0243-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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17
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Vlašínová H, Neděla V, Đorđević B, Havel L. Bottlenecks in bog pine multiplication by somatic embryogenesis and their visualization with the environmental scanning electron microscope. PROTOPLASMA 2017; 254:1487-1497. [PMID: 27783182 DOI: 10.1007/s00709-016-1036-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 10/17/2016] [Indexed: 05/03/2023]
Abstract
Somatic embryogenesis (SE) is an important biotechnological technique used for the propagation of many pine species in vitro. However, in bog pine, one of the most endangered tree species in the Czech Republic, limitations were observed, which negatively influenced the development and further germination of somatic embryos. Although initiation frequency was very low-0.95 %, all obtained cell lines were subjected to maturation. The best responding cell line (BC1) was used and subjected to six different variants of the maturation media. The media on which the highest number of early-precotyledonary/cotyledonary somatic embryos was formed was supplemented with 121 μM abscisic acid (ABA) and with 6 % maltose. In the end of maturation experiments, different abnormalities in formation of somatic embryos were observed. For visualization and identification of abnormalities in meristem development during proliferation and maturation processes, the environmental scanning electron microscope was used. In comparison to the classical light microscope, the non-commercial environmental scanning electron microscope AQUASEM II has been found as a very useful tool for the quick recognition of apical meristem disruption and abnormal development. To our knowledge, this is the first report discussing somatic embryogenesis in bog pine. Based on this observation, the cultivation procedure could be enhanced and the method for SE of bog pine optimized.
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Affiliation(s)
- Helena Vlašínová
- Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, Brno, 613 00, Czech Republic
| | - Vilem Neděla
- Institute of Scientific Instruments, Academy of Sciences of the Czech Republic, Královopolská 147, Brno, 61264, Czech Republic
| | - Biljana Đorđević
- Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, Brno, 613 00, Czech Republic.
| | - Ladislav Havel
- Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, Brno, 613 00, Czech Republic
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Neděla V, Hřib J, Havel L, Hudec J, Runštuk J. Imaging of Norway spruce early somatic embryos with the ESEM, Cryo-SEM and laser scanning microscope. Micron 2016; 84:67-71. [PMID: 26954464 DOI: 10.1016/j.micron.2016.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/19/2016] [Accepted: 02/20/2016] [Indexed: 12/01/2022]
Abstract
This article describes the surface structure of Norway spruce early somatic embryos (ESEs) as a typical culture with asynchronous development. The microstructure of extracellular matrix covering ESEs were observed using the environmental scanning electron microscope as a primary tool and using the scanning electron microscope with cryo attachment and laser electron microscope as a complementary tool allowing our results to be proven independently. The fresh samples were observed in conditions of the air environment of the environmental scanning electron microscope (ESEM) with the pressure from 550Pa to 690Pa and the low temperature of the sample from -18°C to -22°C. The samples were studied using two different types of detector to allow studying either the thin surface structure or material composition. The scanning electron microscope with cryo attachment was used for imaging frozen extracellular matrix microstructure with higher resolution. The combination of both electron microscopy methods was suitable for observation of "native" plant samples, allowing correct evaluation of our results, free of error and artifacts.
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Affiliation(s)
- Vilém Neděla
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the CAS, Brno, Czech Republic.
| | - Jiří Hřib
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the CAS, Brno, Czech Republic
| | - Ladislav Havel
- Department of Plant Biology, Faculty of Agronomy, Mendel University in Brno, Brno, Czech Republic
| | - Jiří Hudec
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the CAS, Brno, Czech Republic
| | - Jiří Runštuk
- Environmental Electron Microscopy Group, Institute of Scientific Instruments of the CAS, Brno, Czech Republic
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WALKER SHAUNC, ALLEN STEPHANIE, BELL GORDON, ROBERTS CLIVEJ. Analysis of leaf surfaces using scanning ion conductance microscopy. J Microsc 2015; 258:119-26. [DOI: 10.1111/jmi.12225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 12/23/2014] [Indexed: 11/28/2022]
Affiliation(s)
- SHAUN C. WALKER
- Laboratory of Biophysics and Surface Analysis, School of Pharmacy; The University of Nottingham; University Park Nottingham UK
| | - STEPHANIE. ALLEN
- Laboratory of Biophysics and Surface Analysis, School of Pharmacy; The University of Nottingham; University Park Nottingham UK
| | - GORDON BELL
- Syngenta, Jealotts Hill International Research Centre; Bracknell Berkshire UK
| | - CLIVE J. ROBERTS
- Laboratory of Biophysics and Surface Analysis, School of Pharmacy; The University of Nottingham; University Park Nottingham UK
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