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Anjum F, Kaushik K, Salam A, Yadav A, Nandi CK. Super-Resolution Microscopy Unveils Synergistic Structural Changes of Organelles Upon Point Mutation. Adv Biol (Weinh) 2024; 8:e2300399. [PMID: 38053236 DOI: 10.1002/adbi.202300399] [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: 08/03/2023] [Revised: 11/02/2023] [Indexed: 12/07/2023]
Abstract
Ethyl methanesulphonate (EMS), is a widely used chemical mutagen that causes high-frequency germline null mutation by inserting an alkyl group into the nucleotide guanine in eukaryotic cells. The effect of EMS on the dynamics of the aneuploid genome, increased cellular instability, and carcinogenicity in relation to benign and malignant tumors are reported, but the molecular level understanding of morphological changes of higher-order chromatin structure has poorly been understood. This is due to a lack of sufficient resolution in conventional microscopic techniques to see small structures below the diffraction limit. Here, using super-resolution radial fluctuation, a largely fragmented, decompaction, and less dense heterochromatin structure upon EMS treatment to HEK 293A cells without any change in nuclear DNA domains is observed. This result suggests an early stage of carcinogenicity happened due to the point mutation. In addition, the distinct structural changes with an elongated morphology of lysosomes are also observed. On the other hand, fragmented and increased heterogeneous populations with an increased cytoplasmic occupancy of mitochondria are observed.
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Affiliation(s)
- Farhan Anjum
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India
| | - Kush Kaushik
- School of Chemical Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India
| | - Abdul Salam
- School of Chemical Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India
| | - Aditya Yadav
- School of Chemical Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India
| | - Chayan Kanti Nandi
- School of Chemical Sciences, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, 175005, India
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Vickery WM, Wood HB, Orlando JD, Singh J, Deng C, Li L, Zhou JY, Lanni F, Porter AW, Sydlik SA. Environmental and health impacts of functional graphenic materials and their ultrasonically altered products. NANOIMPACT 2023; 31:100471. [PMID: 37315844 DOI: 10.1016/j.impact.2023.100471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/16/2023]
Abstract
Graphenic materials have excited the scientific community due to their exciting mechanical, thermal, and optoelectronic properties for a potential range of applications. Graphene and graphene derivatives have demonstrated application in areas stretching from composites to medicine; however, the environmental and health impacts of these materials have not been sufficiently characterized. Graphene oxide (GO) is one of the most widely used graphenic derivatives due to a relatively easy and scalable synthesis, and the ability to tailor the oxygen containing functional groups through further chemical modification. In this paper, ecological and health impacts of fresh and ultrasonically altered functional graphenic materials (FGMs) were investigated. Model organisms, specifically Escherichia coli, Bacillus subtilis, and Caenorhabditis elegans, were used to assess the consequences of environmental exposure to fresh and ultrasonically altered FGMs. FGMs were selected to evaluate the environmental effects of aggregation state, degree of oxidation, charge, and ultrasonication. The major findings indicate that bacterial cell viability, nematode fertility, and nematode movement were largely unaffected, suggesting that a wide variety of FGMs may not pose significant health and environmental risks.
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Affiliation(s)
- Walker M Vickery
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Hunter B Wood
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Jason D Orlando
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Juhi Singh
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Chenyun Deng
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, United States
| | - Li Li
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Jing-Yi Zhou
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Frederick Lanni
- Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States
| | - Aidan W Porter
- Department of Pediatrics, Nephrology Division, University of Pittsburgh School of Medicine, 5th and Ruskin Ave, Pittsburg, PA 15260, United States; Division of Nephrology, Children's Hospital of Pittsburgh, 4401 Penn Ave, Pittsburgh, PA 15224, United States
| | - Stefanie A Sydlik
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, United States; Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, United States.
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Cho JY, Choi TW, Kim SH, Ahnn J, Lee SK. Morphological Characterization of small, dumpy, and long Phenotypes in Caenorhabditis elegans. Mol Cells 2021; 44:160-167. [PMID: 33692220 PMCID: PMC8019597 DOI: 10.14348/molcells.2021.2236] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/18/2021] [Accepted: 02/22/2021] [Indexed: 11/27/2022] Open
Abstract
The determinant factors of an organism's size during animal development have been explored from various angles but remain partially understood. In Caenorhabditis elegans, many genes affecting cuticle structure, cell growth, and proliferation have been identified to regulate the worm's overall morphology, including body size. While various mutations in those genes directly result in changes in the morphological phenotypes, there is still a need for established, clear, and distinct standards to determine the apparent abnormality in a worm's size and shape. In this study, we measured the body length, body width, terminal bulb length, and head size of mutant worms with reported Dumpy (Dpy), Small (Sma) or Long (Lon) phenotypes by plotting and comparing their respective ratios of various parameters. These results show that the Sma phenotypes are proportionally smaller overall with mild stoutness, and Dpy phenotypes are significantly stouter and have disproportionally small head size. This study provides a standard platform for determining morphological phenotypes designating and annotating mutants that exhibit body shape variations, defining the morphological phenotype of previously unexamined mutants.
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Affiliation(s)
- Joshua Young Cho
- Department of Life Science, School of Natural Sciences, Hanyang University, Seoul 04763, Korea
- BK21 PLUS Life Science for BDR Team, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea
- Present address: Doctor of Dental Surgery Program, University of the Pacific, Arthur A. Dugoni School of Dentistry, San Francisco, CA 94103, USA
| | - Tae-Woo Choi
- Department of Life Science, School of Natural Sciences, Hanyang University, Seoul 04763, Korea
- BK21 PLUS Life Science for BDR Team, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea
- Present address: Macrogen Inc., Seoul 08511, Korea
| | - Seung Hyun Kim
- Department of Life Science, School of Natural Sciences, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Joohong Ahnn
- Department of Life Science, School of Natural Sciences, Hanyang University, Seoul 04763, Korea
- BK21 PLUS Life Science for BDR Team, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Sun-Kyung Lee
- Department of Life Science, School of Natural Sciences, Hanyang University, Seoul 04763, Korea
- BK21 PLUS Life Science for BDR Team, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Korea
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Regulation of Actin Dynamics in the C. elegans Somatic Gonad. J Dev Biol 2019; 7:jdb7010006. [PMID: 30897735 PMCID: PMC6473838 DOI: 10.3390/jdb7010006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 03/13/2019] [Accepted: 03/15/2019] [Indexed: 11/25/2022] Open
Abstract
The reproductive system of the hermaphroditic nematode C. elegans consists of a series of contractile cell types—including the gonadal sheath cells, the spermathecal cells and the spermatheca–uterine valve—that contract in a coordinated manner to regulate oocyte entry and exit of the fertilized embryo into the uterus. Contraction is driven by acto-myosin contraction and relies on the development and maintenance of specialized acto-myosin networks in each cell type. Study of this system has revealed insights into the regulation of acto-myosin network assembly and contractility in vivo.
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Wirshing ACE, Cram EJ. Spectrin regulates cell contractility through production and maintenance of actin bundles in the Caenorhabditis elegans spermatheca. Mol Biol Cell 2018; 29:2433-2449. [PMID: 30091661 PMCID: PMC6233056 DOI: 10.1091/mbc.e18-06-0347] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Disruption to the contractility of cells, including smooth muscle cells of the cardiovascular system and myoepithelial cells of the glandular epithelium, contributes to the pathophysiology of contractile tissue diseases, including asthma, hypertension, and primary Sjögren's syndrome. Cell contractility is determined by myosin activity and actomyosin network organization and is mediated by hundreds of protein-protein interactions, many directly involving actin. Here we use a candidate RNA interference screen of more than 100 Caenorhabditis elegans genes with predicted actin-binding and regulatory domains to identify genes that contribute to the contractility of the somatic gonad. We identify the spectrin cytoskeleton composed of SPC-1/α-spectrin, UNC-70/β-spectrin, and SMA-1/β heavy-spectrin as required for contractility and actin organization in the myoepithelial cells of the C. elegans spermatheca. We use imaging of fixed and live animals as well as tissue- and developmental-stage-specific disruption of the spectrin cytoskeleton to show that spectrin regulates the production of prominent central actin bundles and is required for maintenance of central actin bundles throughout successive rounds of stretch and contraction. We conclude that the spectrin cytoskeleton contributes to spermathecal contractility by promoting maintenance of the robust actomyosin bundles that drive contraction.
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Affiliation(s)
| | - Erin J Cram
- Department of Biology, Northeastern University, Boston, MA 02115
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Abstract
PHA-1 encodes a cytoplasmic protein that is required for embryonic morphogenesis and attachment of the foregut (pharynx) to the mouth (buccal capsule). Previous reports have in some cases suggested that PHA-1 is essential for the differentiation of most or all pharyngeal cell types. By performing mosaic analysis with a recently acquired pha-1 null mutation (tm3671), we found that PHA-1 is not required within most or all pharyngeal cells for their proper specification, differentiation, or function. Rather, our evidence suggests that PHA-1 acts in the arcade or anterior epithelial cells of the pharynx to promote attachment of the pharynx to the future buccal capsule. In addition, PHA-1 appears to be required in the epidermis for embryonic morphogenesis, in the excretory system for osmoregulation, and in the somatic gonad for normal ovulation and fertility. PHA-1 activity is also required within at least a subset of intestinal cells for viability. To better understand the role of PHA-1 in the epidermis, we analyzed several apical junction markers in pha-1(tm3671) homozygous embryos. PHA-1 regulates the expression of several components of two apical junction complexes including AJM-1–DLG-1/discs large complex and the classical cadherin–catenin complex, which may account for the role of PHA-1 in embryonic morphogenesis.
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Pilon M. Developmental genetics of the Caenorhabditis elegans pharynx. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2014; 3:263-80. [PMID: 25262818 PMCID: PMC4314705 DOI: 10.1002/wdev.139] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 04/03/2014] [Accepted: 04/15/2014] [Indexed: 11/07/2022]
Abstract
The Caenorhabditis elegans pharynx is a rhythmically pumping organ composed initially of 80 cells that, through fusions, amount to 62 cells in the adult worm. During the first 100 min of development, most future pharyngeal cells are born and gather into a double-plate primordium surrounded by a basal lamina. All pharyngeal cells express the transcription factor PHA-4, of which the concentration increases throughout development, triggering a sequential activation of genes with promoters responding differentially to PHA-4 protein levels. The oblong-shaped pharyngeal primordium becomes polarized, many cells taking on wedge shapes with their narrow ends toward the center, hence forming an epithelial cyst. The primordium then elongates, and reorientations of the cells at the anterior and posterior ends form the mouth and pharyngeal-intestinal openings, respectively. The 20 pharyngeal neurons establish complex but reproducible trajectories using 'fishing line' and growth cone-driven mechanisms, and the gland cells also similarly develop their processes. The genetics behind many fate decisions and morphogenetic processes are being elucidated, and reveal the pharynx to be a fruitful model for developmental biologists.
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Affiliation(s)
- Marc Pilon
- Department of Chemistry and Molecular Biology, University of GothenburgGothenburg, Sweden
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Huang TF, Cho CY, Cheng YT, Huang JW, Wu YZ, Yeh AYC, Nishiwaki K, Chang SC, Wu YC. BLMP-1/Blimp-1 regulates the spatiotemporal cell migration pattern in C. elegans. PLoS Genet 2014; 10:e1004428. [PMID: 24968003 PMCID: PMC4072510 DOI: 10.1371/journal.pgen.1004428] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 04/20/2014] [Indexed: 12/31/2022] Open
Abstract
Spatiotemporal regulation of cell migration is crucial for animal development and organogenesis. Compared to spatial signals, little is known about temporal signals and the mechanisms integrating the two. In the Caenorhabditis elegans hermaphrodite, the stereotyped migration pattern of two somatic distal tip cells (DTCs) is responsible for shaping the gonad. Guidance receptor UNC-5 is necessary for the dorsalward migration of DTCs. We found that BLMP-1, similar to the mammalian zinc finger transcription repressor Blimp-1/PRDI-BF1, prevents precocious dorsalward turning by inhibiting precocious unc-5 transcription and is only expressed in DTCs before they make the dorsalward turn. Constitutive expression of blmp-1 when BLMP-1 would normally disappear delays unc-5 transcription and causes turn retardation, demonstrating the functional significance of blmp-1 down-regulation. Correct timing of BLMP-1 down-regulation is redundantly regulated by heterochronic genes daf-12, lin-29, and dre-1, which regulate the temporal fates of various tissues. DAF-12, a steroid hormone receptor, and LIN-29, a zinc finger transcription factor, repress blmp-1 transcription, while DRE-1, the F-Box protein of an SCF ubiquitin ligase complex, binds to BLMP-1 and promotes its degradation. We have therefore identified a gene circuit that integrates the temporal and spatial signals and coordinates with overall development of the organism to direct cell migration during organogenesis. The tumor suppressor gene product FBXO11 (human DRE-1 ortholog) also binds to PRDI-BF1 in human cell cultures. Our data suggest evolutionary conservation of these interactions and underscore the importance of DRE-1/FBXO11-mediated BLMP-1/PRDI-BF1 degradation in cellular state transitions during metazoan development. The migratory path of DTCs determines the shape of the C. elegans gonad. How the spatiotemporal migration pattern is regulated is not clear. We identified a conserved transcription factor BLMP-1 as a central component of a gene regulatory circuit required for the spatiotemporal control of DTC migration. BLMP-1 levels regulate the timing of the DTC dorsal turn, as high levels delay the turn and low levels result in an early turn. We identify and characterize upstream regulators that control BLMP-1 levels. These regulators function in two ways, i.e. by destabilization of BLMP-1 through ubiquitin-mediated proteolysis and by transcriptional repression of the blmp-1 gene to down-regulate BLMP-1. Interestingly, blmp-1 also negatively controls these regulators. Our data suggest that a dietary signal input acts together with a double-negative feedback loop to switch DTCs from the “blmp-1-on” to the “blmp-1-off” state, promoting their dorsal turn. Furthermore, we show that some protein interactions in the circuit are conserved in C. elegans and humans. Our work defines a novel function of the conserved blmp-1 gene in the temporal control of cell migration, and establishes a gene regulatory circuit that integrates the temporal and spatial inputs to direct cell migration during organogenesis.
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Affiliation(s)
- Tsai-Fang Huang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Chun-Yi Cho
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yi-Ting Cheng
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Jheng-Wei Huang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yun-Zhe Wu
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Athena Yi-Chun Yeh
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Kiyoji Nishiwaki
- Department of Bioscience, Kwansei Gakuin University, Gakuen, Sanda, Japan
| | - Shih-Chung Chang
- Department of Biochemical Science and Technology, National Taiwan University, Taipei, Taiwan
| | - Yi-Chun Wu
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
- Center for Systems Biology, National Taiwan University, Taipei, Taiwan
- Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
- * E-mail:
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