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Song J, Kang J, Kang U, Nam HS, Kim HJ, Kim RH, Kim JW, Yoo H. SNR enhanced high-speed two-photon microscopy using a pulse picker and time gating detection. Sci Rep 2023; 13:14244. [PMID: 37648768 PMCID: PMC10468500 DOI: 10.1038/s41598-023-41270-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 08/24/2023] [Indexed: 09/01/2023] Open
Abstract
Two-photon microscopy (TPM) is an attractive biomedical imaging method due to its large penetration depth and optical sectioning capability. In particular, label-free autofluorescence imaging offers various advantages for imaging biological samples. However, relatively low intensity of autofluorescence leads to low signal-to-noise ratio (SNR), causing practical challenges for imaging biological samples. In this study, we present TPM using a pulse picker to utilize low pulse repetition rate of femtosecond pulsed laser to increase the pulse peak power of the excitation source leading to higher emission of two-photon fluorescence with the same average illumination power. Stronger autofluorescence emission allowed us to obtain higher SNR images of arterial and liver tissues. In addition, by applying the time gating detection method to the pulse signals obtained by TPM, we were able to significantly reduce the background noise of two-photon images. As a result, our TPM system using the pulsed light source with a 19 times lower repetition rate allowed us to obtain the same SNR image more than 19 times faster with the same average power. Although high pulse energy can increase the photobleaching, we also observed that high-speed imaging with low total illumination energy can mitigate the photobleaching effect to a level similar to that of conventional illumination with a high repetition rate. We anticipate that this simple approach will provide guidance for SNR enhancement with high-speed imaging in TPM as well as other nonlinear microscopy.
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Affiliation(s)
- Jeonggeun Song
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Daejeon, 34141, South Korea
| | - Juehyung Kang
- Department of Biomedical Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul, 04763, Republic of Korea
| | - Ungyo Kang
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Daejeon, 34141, South Korea
| | - Hyeong Soo Nam
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Daejeon, 34141, South Korea
| | - Hyun Jung Kim
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Seoul, 08308, South Korea
| | - Ryeong Hyeon Kim
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Seoul, 08308, South Korea
| | - Jin Won Kim
- Cardiovascular Center, Korea University Guro Hospital, 148 Gurodong-Ro, Seoul, 08308, South Korea
| | - Hongki Yoo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-Ro, Daejeon, 34141, South Korea.
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Prusicki MA, Balboni M, Sofroni K, Hamamura Y, Schnittger A. Caught in the Act: Live-Cell Imaging of Plant Meiosis. FRONTIERS IN PLANT SCIENCE 2021; 12:718346. [PMID: 34992616 PMCID: PMC8724559 DOI: 10.3389/fpls.2021.718346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 11/29/2021] [Indexed: 06/14/2023]
Abstract
Live-cell imaging is a powerful method to obtain insights into cellular processes, particularly with respect to their dynamics. This is especially true for meiosis, where chromosomes and other cellular components such as the cytoskeleton follow an elaborate choreography over a relatively short period of time. Making these dynamics visible expands understanding of the regulation of meiosis and its underlying molecular forces. However, the analysis of meiosis by live-cell imaging is challenging; specifically in plants, a temporally resolved understanding of chromosome segregation and recombination events is lacking. Recent advances in live-cell imaging now allow the analysis of meiotic events in plants in real time. These new microscopy methods rely on the generation of reporter lines for meiotic regulators and on the establishment of ex vivo culture and imaging conditions, which stabilize the specimen and keep it alive for several hours or even days. In this review, we combine an overview of the technical aspects of live-cell imaging in plants with a summary of outstanding questions that can now be addressed to promote live-cell imaging in Arabidopsis and other plant species and stimulate ideas on the topics that can be addressed in the context of plant meiotic recombination.
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Affiliation(s)
| | | | | | | | - Arp Schnittger
- Department of Developmental Biology, Institute for Plant Science and Microbiology, University of Hamburg, Hamburg, Germany
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3
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Mursalimov S, Ohno N, Matsumoto M, Bayborodin S, Deineko E. Serial Block-Face Scanning Electron Microscopy Reveals That Intercellular Nuclear Migration Occurs in Most Normal Tobacco Male Meiocytes. FRONTIERS IN PLANT SCIENCE 2021; 12:672642. [PMID: 34025709 PMCID: PMC8138938 DOI: 10.3389/fpls.2021.672642] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/07/2021] [Indexed: 05/14/2023]
Abstract
Serial block-face scanning electron microscopy (SBF-SEM) was used here to study tobacco male meiosis. Three-dimensional ultrastructural analyses revealed that intercellular nuclear migration (INM) occurs in 90-100% of tobacco meiocytes. At the very beginning of meiosis, every meiocyte connected with neighboring cells by more than 100 channels was capable of INM. At leptotene and zygotene, the nucleus in most tobacco meiocytes approached the cell wall and formed nuclear protuberances (NPs) that crossed the cell wall through the channels and extended into the cytoplasm of a neighboring cell. The separation of NPs from the migrating nuclei and micronuclei formation were not observed. In some cases, the NPs and nuclei of neighboring cells appeared apposed to each other, and the gap between their nuclear membranes became invisible. At pachytene, NPs retracted into their own cells. After that, the INM stopped. We consider INM a normal part of tobacco meiosis, but the reason for such behavior of nuclei is unclear. The results obtained by SBF-SEM suggest that there are still many unexplored features of plant meiosis hidden by limitations of common types of microscopy and that SBF-SEM can turn over a new leaf in plant meiosis research.
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Affiliation(s)
- Sergey Mursalimov
- Laboratory of Plant Bioengineering, Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
- *Correspondence: Sergey Mursalimov
| | - Nobuhiko Ohno
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
- Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, Japan
| | - Mami Matsumoto
- Section of Electron Microscopy, Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Japan
| | - Sergey Bayborodin
- Laboratory of Plant Bioengineering, Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Elena Deineko
- Laboratory of Plant Bioengineering, Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
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4
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Valuchova S, Mikulkova P, Pecinkova J, Klimova J, Krumnikl M, Bainar P, Heckmann S, Tomancak P, Riha K. Imaging plant germline differentiation within Arabidopsis flowers by light sheet microscopy. eLife 2020; 9:52546. [PMID: 32041682 DOI: 10.7554/elife.52546.sa2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 01/04/2020] [Indexed: 05/27/2023] Open
Abstract
In higher plants, germline differentiation occurs during a relatively short period within developing flowers. Understanding of the mechanisms that govern germline differentiation lags behind other plant developmental processes. This is largely because the germline is restricted to relatively few cells buried deep within floral tissues, which makes them difficult to study. To overcome this limitation, we have developed a methodology for live imaging of the germ cell lineage within floral organs of Arabidopsis using light sheet fluorescence microscopy. We have established reporter lines, cultivation conditions, and imaging protocols for high-resolution microscopy of developing flowers continuously for up to several days. We used multiview imagining to reconstruct a three-dimensional model of a flower at subcellular resolution. We demonstrate the power of this approach by capturing male and female meiosis, asymmetric pollen division, movement of meiotic chromosomes, and unusual restitution mitosis in tapetum cells. This method will enable new avenues of research into plant sexual reproduction.
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Affiliation(s)
- Sona Valuchova
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Pavlina Mikulkova
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Jana Pecinkova
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Jana Klimova
- IT4Innovations, VSB-Technical University of Ostrava, Ostrava, Czech Republic
| | - Michal Krumnikl
- IT4Innovations, VSB-Technical University of Ostrava, Ostrava, Czech Republic
- Department of Computer Science, FEECS VSB - Technical University of Ostrava, Ostrava, Czech Republic
| | - Petr Bainar
- IT4Innovations, VSB-Technical University of Ostrava, Ostrava, Czech Republic
| | - Stefan Heckmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Pavel Tomancak
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Karel Riha
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
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5
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Valuchova S, Mikulkova P, Pecinkova J, Klimova J, Krumnikl M, Bainar P, Heckmann S, Tomancak P, Riha K. Imaging plant germline differentiation within Arabidopsis flowers by light sheet microscopy. eLife 2020; 9:e52546. [PMID: 32041682 PMCID: PMC7012603 DOI: 10.7554/elife.52546] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 01/04/2020] [Indexed: 12/21/2022] Open
Abstract
In higher plants, germline differentiation occurs during a relatively short period within developing flowers. Understanding of the mechanisms that govern germline differentiation lags behind other plant developmental processes. This is largely because the germline is restricted to relatively few cells buried deep within floral tissues, which makes them difficult to study. To overcome this limitation, we have developed a methodology for live imaging of the germ cell lineage within floral organs of Arabidopsis using light sheet fluorescence microscopy. We have established reporter lines, cultivation conditions, and imaging protocols for high-resolution microscopy of developing flowers continuously for up to several days. We used multiview imagining to reconstruct a three-dimensional model of a flower at subcellular resolution. We demonstrate the power of this approach by capturing male and female meiosis, asymmetric pollen division, movement of meiotic chromosomes, and unusual restitution mitosis in tapetum cells. This method will enable new avenues of research into plant sexual reproduction.
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Affiliation(s)
- Sona Valuchova
- Central European Institute of Technology (CEITEC)Masaryk UniversityBrnoCzech Republic
| | - Pavlina Mikulkova
- Central European Institute of Technology (CEITEC)Masaryk UniversityBrnoCzech Republic
| | - Jana Pecinkova
- Central European Institute of Technology (CEITEC)Masaryk UniversityBrnoCzech Republic
| | - Jana Klimova
- IT4InnovationsVSB–Technical University of OstravaOstravaCzech Republic
| | - Michal Krumnikl
- IT4InnovationsVSB–Technical University of OstravaOstravaCzech Republic
- Department of Computer ScienceFEECS VSB – Technical University of OstravaOstravaCzech Republic
| | - Petr Bainar
- IT4InnovationsVSB–Technical University of OstravaOstravaCzech Republic
| | - Stefan Heckmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK)SeelandGermany
| | - Pavel Tomancak
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Karel Riha
- Central European Institute of Technology (CEITEC)Masaryk UniversityBrnoCzech Republic
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6
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Prusicki MA, Keizer EM, van Rosmalen RP, Komaki S, Seifert F, Müller K, Wijnker E, Fleck C, Schnittger A. Live cell imaging of meiosis in Arabidopsis thaliana. eLife 2019; 8:e42834. [PMID: 31107238 PMCID: PMC6559805 DOI: 10.7554/elife.42834] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 05/17/2019] [Indexed: 11/13/2022] Open
Abstract
To follow the dynamics of meiosis in the model plant Arabidopsis, we have established a live cell imaging setup to observe male meiocytes. Our method is based on the concomitant visualization of microtubules (MTs) and a meiotic cohesin subunit that allows following five cellular parameters: cell shape, MT array, nucleus position, nucleolus position, and chromatin condensation. We find that the states of these parameters are not randomly associated and identify 11 cellular states, referred to as landmarks, which occur much more frequently than closely related ones, indicating that they are convergence points during meiotic progression. As a first application of our system, we revisited a previously identified mutant in the meiotic A-type cyclin TARDY ASYNCHRONOUS MEIOSIS (TAM). Our imaging system enabled us to reveal both qualitatively and quantitatively altered landmarks in tam, foremost the formation of previously not recognized ectopic spindle- or phragmoplast-like structures that arise without attachment to chromosomes.
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Affiliation(s)
- Maria A Prusicki
- Department of Developmental BiologyUniversity of HamburgHamburgGermany
| | - Emma M Keizer
- Department of Agrotechnology and Food SciencesWageningen UniversityWageningenThe Netherlands
| | - Rik P van Rosmalen
- Department of Agrotechnology and Food SciencesWageningen UniversityWageningenThe Netherlands
| | - Shinichiro Komaki
- Department of Developmental BiologyUniversity of HamburgHamburgGermany
| | - Felix Seifert
- Department of Developmental BiologyUniversity of HamburgHamburgGermany
| | - Katja Müller
- Department of Developmental BiologyUniversity of HamburgHamburgGermany
| | - Erik Wijnker
- Department of Plant Science, Laboratory of GeneticsWageningen University and ResearchWageningenThe Netherlands
| | - Christian Fleck
- Department of Agrotechnology and Food SciencesWageningen UniversityWageningenThe Netherlands
| | - Arp Schnittger
- Department of Developmental BiologyUniversity of HamburgHamburgGermany
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7
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Feng R, Sun Y, Tian M, Zhang G, Zhang R, Guo L, Li X, Yu X, Zhao N. A membrane-permeable dye for living cells with large two-photon excited fluorescence action cross-sections for bioimaging. J Mater Chem B 2015; 3:8644-8649. [PMID: 32262721 DOI: 10.1039/c5tb00940e] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The development of two-photon fluorophores remains an important issue. Dyes that possess both large two-photon excited fluorescence action cross-sections and cell membrane permeability are especially in demand to maximize the underlying virtue of two-photon microscopy for bioimaging. Herein, a novel two-photon excited fluorescence dye has been synthesized. This V-shaped dye exhibited large two-photon excited fluorescence action cross-sections and high plasma membrane permeability. Cell imaging experiments demonstrated that the dye could stain living cells with bright two-photon excited fluorescence. All the results have indicated the potential of the dye as a basic platform for the development of two-photon excited fluorescence probes.
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Affiliation(s)
- Ruiqing Feng
- Center of Bio & Micro/Nano Functional Materials, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China.
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8
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9
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LIU X, WANG P, FU J, LV D, CHEN D, LI Y, MA W. Two-photon fluorescence real-time imaging on the development of early mouse embryo by stages. J Microsc 2011; 241:212-8. [DOI: 10.1111/j.1365-2818.2010.03426.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Zhao N, Zhang Y, Liu X, Yu X, Ge M. Carbazole tricationic salt: A novel potential two-photon fluorescent DNA probe for nucleic imaging of cells. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s11434-010-4176-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Kelliher T, Walbot V. Emergence and patterning of the five cell types of the Zea mays anther locule. Dev Biol 2010; 350:32-49. [PMID: 21070762 DOI: 10.1016/j.ydbio.2010.11.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 11/02/2010] [Accepted: 11/02/2010] [Indexed: 01/02/2023]
Abstract
One fundamental difference between plants and animals is the existence of a germ-line in animals and its absence in plants. In flowering plants, the sexual organs (stamens and carpels) are composed almost entirely of somatic cells, a small subset of which switch to meiosis; however, the mechanism of meiotic cell fate acquisition is a long-standing botanical mystery. In the maize (Zea mays) anther microsporangium, the somatic tissues consist of four concentric cell layers that surround and support reproductive cells as they progress through meiosis and pollen maturation. Male sterility, defined as the absence of viable pollen, is a common phenotype in flowering plants, and many male sterile mutants have defects in somatic and reproductive cell fate acquisition. However, without a robust model of anther cell fate acquisition based on careful observation of wild-type anther ontogeny, interpretation of cell fate mutants is limited. To address this, the pattern of cell proliferation, expansion, and differentiation was tracked in three dimensions over 30 days of wild-type (W23) anther development, using anthers stained with propidium iodide (PI) and/or 5-ethynyl-2'-deoxyuridine (EdU) (S-phase label) and imaged by confocal microscopy. The pervading lineage model of anther development claims that new cell layers are generated by coordinated, oriented cell divisions in transient precursor cell types. In reconstructing anther cell division patterns, however, we can only confirm this for the origin of the middle layer (ml) and tapetum, while young anther development appears more complex. We find that each anther cell type undergoes a burst of cell division after specification with a characteristic pattern of both cell expansion and division. Comparisons between two inbreds lines and between ab- and adaxial anther florets indicated near identity: anther development is highly canalized and synchronized. Three classical models of plant organ development are tested and ruled out; however, local clustering of developmental events was identified for several processes, including the first evidence for a direct relationship between the development of ml and tapetal cells. We speculate that small groups of ml and tapetum cells function as a developmental unit dedicated to the development of a single pollen grain.
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Affiliation(s)
- Timothy Kelliher
- Stanford University, Department of Biology, 385 Serra Mall, Stanford, CA 94305-5020, USA.
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12
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Liu X, Sun Y, Zhang Y, Zhao N, Zhao H, Wang G, Yu X, Liu H. A Series of Carbazole Cationic Compounds with Large Two-Photon Absorption Cross Sections for Imaging Mitochondria in Living Cells with Two-Photon Fluorescence Microscopy. J Fluoresc 2010; 21:497-506. [DOI: 10.1007/s10895-010-0736-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 09/28/2010] [Indexed: 12/24/2022]
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13
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Chickarmane V, Roeder AH, Tarr PT, Cunha A, Tobin C, Meyerowitz EM. Computational morphodynamics: a modeling framework to understand plant growth. ANNUAL REVIEW OF PLANT BIOLOGY 2010; 61:65-87. [PMID: 20192756 PMCID: PMC4120954 DOI: 10.1146/annurev-arplant-042809-112213] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Computational morphodynamics utilizes computer modeling to understand the development of living organisms over space and time. Results from biological experiments are used to construct accurate and predictive models of growth. These models are then used to make novel predictions that provide further insight into the processes involved, which can be tested experimentally to either confirm or rule out the validity of the computational models. This review highlights two fundamental challenges: (a) to understand the feedback between mechanics of growth and chemical or molecular signaling, and (b) to design models that span and integrate single cell behavior with tissue development. We review different approaches to model plant growth and discuss a variety of model types that can be implemented to demonstrate how the interplay between computational modeling and experimentation can be used to explore the morphodynamics of plant development.
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Affiliation(s)
- Vijay Chickarmane
- Division of Biology, California Institute Technology, Pasadena, California 91125
| | - Adrienne H.K. Roeder
- Division of Biology, California Institute Technology, Pasadena, California 91125
- Center for Integrative Study of Cell Regulation, California Institute Technology, Pasadena, California 91125
| | - Paul T. Tarr
- Division of Biology, California Institute Technology, Pasadena, California 91125
| | - Alexandre Cunha
- Center for Advanced Computing Research, California Institute Technology, Pasadena, California 91125
- Center for Integrative Study of Cell Regulation, California Institute Technology, Pasadena, California 91125
| | - Cory Tobin
- Division of Biology, California Institute Technology, Pasadena, California 91125
| | - Elliot M. Meyerowitz
- Division of Biology, California Institute Technology, Pasadena, California 91125
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Zhang Y, Wang J, Jia P, Yu X, Liu H, Liu X, Zhao N, Huang B. Two-photon fluorescence imaging of DNA in living plant turbid tissue with carbazole dicationic salt. Org Biomol Chem 2010; 8:4582-8. [DOI: 10.1039/c0ob00030b] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Live imaging of rapid chromosome movements in meiotic prophase I in maize. Proc Natl Acad Sci U S A 2009; 106:20989-94. [PMID: 19926853 DOI: 10.1073/pnas.0906498106] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The ability of chromosomes to move across the nuclear space is essential for the reorganization of the nucleus that takes place in early meiotic prophase. Chromosome dynamics of prophase I have been studied in budding and fission yeasts, but little is known about this process in higher eukaryotes, where genomes and chromosomes are much larger and meiosis takes a longer time to complete. This knowledge gap has been mainly caused by difficulties in culturing isolated live meiocytes of multicellular eukaryotes. To study the nuclear dynamics during meiotic prophase in maize, we established a system to observe live meiocytes inside intact anthers. We found that maize chromosomes exhibited extremely dynamic and complex motility in zygonema and pachynema. The movement patterns differed dramatically between the two stages. Chromosome movements included rotations of the entire chromatin and movements of individual chromosome segments, which were mostly telomere-led. Chromosome motility was coincident with dynamic deformations of the nuclear envelope. Both, chromosome and nuclear envelope motility depended on actin microfilaments as well as tubulin. The complexity of the nuclear movements implies that several different mechanisms affect chromosome motility in early meiotic prophase in maize. We propose that the vigorous nuclear motility provides a mechanism for homologous loci to find each other during zygonema.
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Affiliation(s)
- Timothy M Ragan
- Department of Mechanical Engineering, Division of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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