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Cell-cell fusions and cell-in-cell phenomena in healthy cells and cancer: Lessons from protists and invertebrates. Semin Cancer Biol 2021; 81:96-105. [PMID: 33713795 DOI: 10.1016/j.semcancer.2021.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/28/2021] [Accepted: 03/04/2021] [Indexed: 02/08/2023]
Abstract
Herein we analyze two special routes of the multinucleated cells' formation - the fusion of mononuclear cells and the formation of cell-in-cell structures - in the healthy tissues and in tumorigenesis. There are many theories of tumorigenesis based on the phenomenon of emergence of the hybrid cancer cells. We consider the phenomena, which are rarely mentioned in those theories: namely, cellularization of syncytium or coenocytes, and the reversible or irreversible somatogamy. The latter includes the short-term and the long-term vegetative (somatic) cells' fusions in the life cycles of unicellular organisms. The somatogamy and multinuclearity have repeatedly and independently emerged in various groups of unicellular eukaryotes. These phenomena are among dominant survival and biodiversity sustaining strategies in protists and we admit that they can likely play an analogous role in cancer cells.
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Bínová E, Bína D, Nohýnková E. DNA content in Acanthamoeba during two stress defense reactions: Encystation, pseudocyst formation and cell cycle. Eur J Protistol 2020; 77:125745. [PMID: 33218872 DOI: 10.1016/j.ejop.2020.125745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/22/2020] [Accepted: 10/19/2020] [Indexed: 12/01/2022]
Abstract
During environmental stress, the vegetative cells of the facultative pathogenic amoeba Acanthamoeba castellanii reversibly differentiate into resistant dormant stages, namely, cysts or pseudocysts. The type of resistant stage depends on the nature and duration of the stressor. Cell differentiation is accompanied by changes in morphology and cellular metabolism. Moreover, cell differentiation is also expected to be closely linked to the regulation of the cell cycle and, thus, to cellular DNA content. While the existence of the resistant stages in A. castellanii is well known, there is no consensus regarding the relationship between differentiation and cell cycle progression. In the present work, we used flow cytometry analysis to explore the changes in the DNA content during Acanthamoeba encystation and pseudocyst formation. Our results strongly indicate that A. castellanii enters encystation from the G2 phase of the cell cycle. In contrast, differentiation into pseudocysts can begin in the G1 and G2 phases. In addition, we present a phylogenetic analysis and classification of the main cell cycle regulators, namely, cyclin-dependent kinases and cyclins that are found in the genome of A. castellanii.
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Affiliation(s)
- Eva Bínová
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Studnickova 7, 128 00 Prague 2, Czech Republic
| | - David Bína
- Faculty of Science, University of South Bohemia, Branišovská 1760 and The Czech Academy of Sciences, Biology Centre, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Eva Nohýnková
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Studnickova 7, 128 00 Prague 2, Czech Republic.
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3
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Autophagy inhibitors as a potential antiamoebic treatment for Acanthamoeba keratitis. Antimicrob Agents Chemother 2015; 59:4020-5. [PMID: 25896709 DOI: 10.1128/aac.05165-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 04/16/2015] [Indexed: 02/06/2023] Open
Abstract
Acanthamoeba cysts are resistant to extreme physical and chemical conditions. Autophagy is an essential pathway for encystation of Acanthamoeba cells. To evaluate the possibility of an autophagic Acanthamoeba encystation mechanism, we evaluated autophagy inhibitors, such as 3-methyladenine (3MA), LY294002, wortmannin, bafilomycin A, and chloroquine. Among these autophagy inhibitors, the use of 3MA and chloroquine showed a significant reduction in the encystation ratio in Acanthamoeba cells. Wortmannin also inhibited the formation of mature cysts, while LY294002 and bafilomycin A did not affect the encystation of Acanthamoeba cells. Transmission electron microscopy revealed that 3MA and wortmannin inhibited autophagy formation and that chloroquine interfered with the formation of autolysosomes. Inhibition of autophagy or autolysosome formation resulted in a significant block in the encystation in Acanthamoeba cells. Clinical treatment with 0.02% polyhexamethylene biguanide (PHMB) showed high cytopathic effects on Acanthamoeba trophozoites and cysts; however, it also revealed high cytopathic effects on human corneal epithelial cells. In this study, we investigated effects of the combination of a low (0.00125%) concentration of PHMB with each of the autophagy inhibitors 3MA, wortmannin, and chloroquine on Acanthamoeba and human corneal epithelial cells. These new combination treatments showed low cytopathic effects on human corneal cells and high cytopathic effects on Acanthamoeba cells. Taken together, these results provide fundamental information for optimizing the treatment of Acanthamoeba keratitis.
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Lloyd D. Encystment in Acanthamoeba castellanii: a review. Exp Parasitol 2014; 145 Suppl:S20-7. [PMID: 24726698 DOI: 10.1016/j.exppara.2014.03.026] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/02/2014] [Accepted: 03/04/2014] [Indexed: 10/25/2022]
Abstract
Differentiation of Acanthamoeba castellanii trophozoites involves massive turnover of cellular components and remodelling of organelle structure and function so as to produce a cryptobiotic cell, resistant to desiccation, heat, freezing, and chemical treatments. This review presents a summary of a decade of research on the most studied aspects of the biochemistry of this process, with emphasis on problems of biocide and drug resistances, putative new targets, molecular and cell biology of the process of encystment, and the characteristics of the encysted state. As well as the intrinsic pathogenicity of the organism towards the cornea, and the ability of related species to invade the human brain, its propensity for harbouring and transmitting pathogenic bacteria and viruses is considerable and leads to increasing concerns. The long-term survival and resistance of cysts to drugs and biocides adds another layer of complexity to the problem of their elimination.
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Affiliation(s)
- David Lloyd
- School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AT, UK.
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Mattar FE, Byers TJ. Morphological changes and the requirements for macromolecule synthesis during excystment of acanthamoeba castellanii. ACTA ACUST UNITED AC 2010; 49:507-19. [PMID: 19866776 PMCID: PMC2108339 DOI: 10.1083/jcb.49.2.507] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Light and phase-contrast microscopic observations of excystment in Acanthamoeba castellanii have been used to classify cells in excysting populations as free trophozoites, or mature, activated, or preemergent cysts. These categories have been used to describe the kinetics of excystment. A pH of 7 and a temperature of 30°C have been found to be optimal for the activation of mature cysts. Both activation and emergence are inhibited by cycloheximide and actinomycin D, but neither process is much affected by hydroxyurea. Cell-free extracts of high molecular weight components of cyst cytoplasm can support protein synthesis in vitro, although less efficiently than similar extracts from trophozoites. Evidence indicates that some of the functional RNA in the cyst extracts is synthesized before excystment.
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Affiliation(s)
- F E Mattar
- Academic Faculty of Microbial and Cellular Biology and the Zoology Graduate Program, The Ohio State University, Columbus, Ohio 43210
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6
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Rudick VL. Relationships between nucleic Acid synthetic patterns and encystment in aging unagitated cultures of acanthamoeba castellanii. ACTA ACUST UNITED AC 2010; 49:498-506. [PMID: 19866775 PMCID: PMC2108340 DOI: 10.1083/jcb.49.2.498] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Changes in the levels of DNA and RNA syntheses have been studied in unagitated cultures of Acanthamoeba castellanii during the phases of logarithmic multiplication (LM) and population growth deceleration (PGD). Pulse-labeling experiments show that the rate of DNA synthesis decreases at the same time that DNA per cell is known to drop by 50%. The drop in DNA content has been explained by demonstrating with hydroxyurea that the majority of LM amebas can replicate once when DNA synthesis is inhibited and, therefore, must be in G(2), whereas the PGD amebas cannot multiply in the presence of inhibitor and, therefore, must be in G(1). The inhibition of DNA synthesis in LM or PGD cells has been shown to induce encystment. The rate of RNA synthesis, as illustrated by pulse-labeling experiments, increases 25% in late LM-early PGD while RNA per cell increases 75%. The rate of synthesis then decreases 65%. The majority of accumulated RNA has been demonstrated to be ribosomal by disc electrophoresis. By using actinomycin D at different stages during the RNA build-up, the ability of the amebas to encyst has been shown to depend on the presence of this RNA. The observations on DNA and RNA are discussed with respect to the occurrence of cysts in the cultures during PGD.
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Affiliation(s)
- V L Rudick
- Graduate Program in Zoology and the Academic Faculty of Microbial and Cellular Biology, The Ohio State University, Columbus, Ohio 43210
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RASTOGI AK, SAGAR P, KAPOOR SC, AGARWALA SC. Action of Ultraviolet Radiation on Excystment and Concomitant Macromolecular Syntheses inSchizopyrenus russelli*. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1550-7408.1972.tb03477.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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IN MEMORIAM: THOMAS J. BYERS (1935-2003). J Eukaryot Microbiol 2004. [DOI: 10.1111/j.1550-7408.2004.tb00403.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schroeder JM, Booton GC, Hay J, Niszl IA, Seal DV, Markus MB, Fuerst PA, Byers TJ. Use of subgenic 18S ribosomal DNA PCR and sequencing for genus and genotype identification of acanthamoebae from humans with keratitis and from sewage sludge. J Clin Microbiol 2001; 39:1903-11. [PMID: 11326011 PMCID: PMC88046 DOI: 10.1128/jcm.39.5.1903-1911.2001] [Citation(s) in RCA: 393] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study identified subgenic PCR amplimers from 18S rDNA that were (i) highly specific for the genus Acanthamoeba, (ii) obtainable from all known genotypes, and (iii) useful for identification of individual genotypes. A 423- to 551-bp Acanthamoeba-specific amplimer ASA.S1 obtained with primers JDP1 and JDP2 was the most reliable for purposes i and ii. A variable region within this amplimer also identified genotype clusters, but purpose iii was best achieved with sequencing of the genotype-specific amplimer GTSA.B1. Because this amplimer could be obtained from any eukaryote, axenic Acanthamoeba cultures were required for its study. GTSA.B1, produced with primers CRN5 and 1137, extended between reference bp 1 and 1475. Genotypic identification relied on three segments: bp 178 to 355, 705 to 926, and 1175 to 1379. ASA.S1 was obtained from single amoeba, from cultures of all known 18S rDNA genotypes, and from corneal scrapings of Scottish patients with suspected Acanthamoeba keratitis (AK). The AK PCR findings were consistent with culture results for 11 of 15 culture-positive specimens and detected Acanthamoeba in one of nine culture-negative specimens. ASA.S1 sequences were examined for 6 of the 11 culture-positive isolates and were most closely associated with genotypic cluster T3-T4-T11. A similar distance analysis using GTSA.B1 sequences identified nine South African AK-associated isolates as genotype T4 and three isolates from sewage sludge as genotype T5. Our results demonstrate the usefulness of 18S ribosomal DNA PCR amplimers ASA.S1 and GTSA.B1 for Acanthamoeba-specific detection and reliable genotyping, respectively, and provide further evidence that T4 is the predominant genotype in AK.
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Affiliation(s)
- J M Schroeder
- Department of Molecular Genetics, The Ohio State University, 484 W. 12th Ave., Columbus, OH 43210, USA
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AVERY SIMONV, LLOYD DAVID, HARWOOD JOHNL. Changes in Membrane Fatty Acid Composition and ?12-Desaturase Activity during Growth of Acanthamoeba castellanii in Batch Culture. J Eukaryot Microbiol 1994. [DOI: 10.1111/j.1550-7408.1994.tb06096.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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LASMAN MARIA. Encystment-Inducing Factor from Cultures of Acanthamoeba palestinensis. (Acanthamoeba palestinensis/growth/cyst formation/encystment-inducing factor). Dev Growth Differ 1987. [DOI: 10.1111/j.1440-169x.1987.00547.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Poulin R, Larochelle J, Hellebust JA. The regulation of amino acid metabolism during hyperosmotic stress inAcanthamoeba castellanii. ACTA ACUST UNITED AC 1987. [DOI: 10.1002/jez.1402430303] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Byers TJ. Molecular biology of DNA in Acanthamoeba, Amoeba, Entamoeba, and Naegleria. INTERNATIONAL REVIEW OF CYTOLOGY 1986; 99:311-41. [PMID: 3514511 DOI: 10.1016/s0074-7696(08)61430-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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14
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Fenchel T, Finlay BJ. Respiration rates in heterotrophic, free-living protozoa. MICROBIAL ECOLOGY 1983; 9:99-122. [PMID: 24221648 DOI: 10.1007/bf02015125] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Published estimates of protozoan respiratory rates are reviewed with the object of clarifying their value in ecological studies. The data show a surprisingly large variance when similarly sized cells or individual species are compared. This is attributed to the range of physiological states in the cells concerned. The concept of basal metabolism has little meaning in protozoa. During balanced growth, energy metabolism is nearly linearly proportional to the growth rate constant; at the initiation of starvation, metabolic rate rapidly declines. Motility requires an insignificant fraction of the energy budget of protozoans. For growing cells, metabolic rate is approximately proportional to weight(0.75) and the data fall nearly exactly on a curve extrapolated from that describing the respiration rates of poikilotherm metazoans as a function of body weight. It is conceivable that protozoan species exist with lower maximum potential growth and metabolic rates than those predicted from cell volume and the equations derived from the available data. However, the lack of information concerning the state of the cells studied prevents verification of this idea. Laboratory measurements of protozoan respiratory rates have no predictive value for protozoa in nature other than delimiting a potential range. For small protozoans, this range may, on an individual basis, represent a factor of 50.
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Affiliation(s)
- T Fenchel
- Institute of Ecology and Genetics, University of Aarhus, DK-8000, Aarhus C, Denmark
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15
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Smart-Nixon S, Schumm DE, Webb TE. Organ and species specificity of the messenger RNA transport factor. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1983; 75:665-9. [PMID: 6352163 DOI: 10.1016/0305-0491(83)90113-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The transport of messenger RNA from isolated rat liver nuclei is dependent on a 35,000 dalton protein localized in the cytoplasm. The tissue and species specificity of this protein are reported. The factor from female rat liver or from rat brain, kidney, or hepatoma supports the transport of messenger RNA from male rat liver nuclei. Messenger RNA is also transported in response to the factor from beef and chicken liver. The cytosols from rat erythrocytes, amoeba and yeast were inactive in the rat liver system. The results indicate that the messenger RNA transport factor is not specific for the nucleotide sequence of the coding portion of the messenger RNA and that it is not organ or species specific within the vertebrates.
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16
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Regulation of fatty acid unsaturation in encystingAcanthamoeba cells. Curr Microbiol 1981. [DOI: 10.1007/bf01567434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Akins RA, Byers TJ. Differentiation promoting factors induced in Acanthamoeba by inhibitors of mitochondrial macromolecule synthesis. Dev Biol 1980; 78:126-40. [PMID: 7399137 DOI: 10.1016/0012-1606(80)90323-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Byers TJ, Akins RA, Maynard BJ, Lefken RA, Martin SM. Rapid growth of Acanthamoeba in defined media; induction of encystment by glucose-acetate starvation. THE JOURNAL OF PROTOZOOLOGY 1980; 27:216-9. [PMID: 7400997 DOI: 10.1111/j.1550-7408.1980.tb04684.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Defined media are described that support 14-20 h generation times for Acanthamoeba castellanii and A. rhysodes in monolayer cultures. The media differ in minor ways from previously described media, but the growth rates are greatly improved over previously reported values. Maximum growth rates were observed for A. castellanii in a complex medium containing 21 amino acids, but near-maximum rates could be achieved in relatively simple media containing 9 amino acids. Growth occurred with 6 amino acids, as reported by others, but generation times exceeded 30 h. Amitosis was a common problem during early subcultures in defined media, defined media by glucose and acetate starvation. The rate of encystment varied with cell density at the time of starvation and was optimal at initial densities of 400-800 amebae/mm2.
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Edwards SW, Lloyd D. Oscillations in protein and RNA content during synchronous growth of Acanthamoeba castellanii. Evidence for periodic turnover of macromolecules during the cell cycle. FEBS Lett 1980; 109:21-6. [PMID: 7353629 DOI: 10.1016/0014-5793(80)81302-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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20
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Baldock BM, Baker JH, Sleigh MA. Laboratory growth rates of six species of freshwater Gymnamoebia. Oecologia 1980; 47:156-159. [PMID: 28309464 DOI: 10.1007/bf00346813] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/1980] [Indexed: 11/25/2022]
Abstract
Laboratory growth rates of six species of Gymnamoebia, isolated from English chalk streams and cultured on bacteria, have been determined at four different temperatures. Generation times ranged from 4.46 to 33.3 h. A linear relationship between log10 specific growth rate and the reciprocal of the absolute temperature was demonstrated for four species. A significant regression of log10 generation time on log10 cell volume was obtained for data on amoebae in combination with data on ciliates taken from the literature. This regression may be used to predict the growth rates of other species of amoebae and ciliates of known cell volume.
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Affiliation(s)
- B M Baldock
- River Laboratory, Freshwater Biological Association, East Stoke, BH20 6BB, Wareham, Dorset
| | - J H Baker
- River Laboratory, Freshwater Biological Association, East Stoke, BH20 6BB, Wareham, Dorset
| | - M A Sleigh
- Department of Biology, University of Southampton, SO93TU, England
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SOBOTA ANDRZEJ. Effect of Monovalent Thallium Ions on Differentiation and Multiplication of Acanthamoeba castellanii. Differentiation 1979. [DOI: 10.1111/j.1432-0436.1979.tb01004.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Byers TJ. Growth, reproduction, and differentiation in Acanthamoeba. INTERNATIONAL REVIEW OF CYTOLOGY 1979; 61:283-338. [PMID: 389870 DOI: 10.1016/s0074-7696(08)62000-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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23
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Seilhamer JJ, Byers TJ. Mutants of Acanthamoeba castellanii resistant to erythromycin, chloramphenicol, and oligomycin. THE JOURNAL OF PROTOZOOLOGY 1978; 25:486-9. [PMID: 739412 DOI: 10.1111/j.1550-7408.1978.tb04172.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cell lines of Acanthamoeba castellanii resistant to erythromycin (EryR), chloramphenicol (CapR), and oligomycin (OliR) have been isolated. These may be the first such mutants for A. castellanii. These mutants have been phenotypically stable for 2 years, surviving storage and vegetative multiplication in the absence of drugs. Resistance was specific for each drug, but double mutants (e.g. EryRCapR) were obtained by stepwise selection. Mutant frequencies were determined in multiwell plates; less than 10 colony forming units (CFU/10(5) amebas were observed in wild-type populations 12 days after incubation in 500 microgram Ery/ml, 2.5 mg Cap/ml, or 15 microgram Oli/ml. After 30 days, averages of 100 CFU/10(5) amebas were observed in Ery and Cap, whereas, frequencies for Oli remained unchanged. Frequencies for EryR and CapR were consistent with rates of recovery from these drugs in batch cultures. We were unable to obtain spontaneous mutants resistant to cycloheximide, emetine, 5-fluorodeoxyuridine, or ethidium bromide. EryR, CapR and OliR could be mitochondria mutants.
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24
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Larochelle J, Gagnon A. Osmoregulation in Acanthamoeba castellanii—III. Relations between dry weight, water, and inorganic ions, and control of the ionic levels. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/0300-9629(78)90317-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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Rastogi AK, Sagar P, Agarwala SC. Correlation of encystment and division in Schizopyrenus russelli. THE JOURNAL OF PROTOZOOLOGY 1977; 24:294-6. [PMID: 328865 DOI: 10.1111/j.1550-7408.1977.tb00980.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Schizopyrenus russelli, a free-living soil ameba, grows and encysts in the presence of bacteria. The encystment occurs with decline in the division rate. This is accompanied by incorporation of [U-14C] glucose into cyst cellulose. The degree of multiplication (but not of encystment) is a function of bacterial concentration. Berenil, a trypanocidal drug, while allowing excystment, completely inhibited multiplication of emerged amebae and their encystment. Addition of this drug after 24 hr, when amebae had gone into a phase of active division failed to check encystment, although it still inhibited further multiplication of the amebae. The findings suggest that a phase of cell division may be a prerequisite for encystment.
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Weik RR, John DT. Cell size, macromolecular composition, and O2 consumption during agitated cultivation of Naegleria gruberi. THE JOURNAL OF PROTOZOOLOGY 1977; 24:196-200. [PMID: 17004 DOI: 10.1111/j.1550-7408.1977.tb05306.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell size, macromolecular composition, carbohydrate utilization patterns, and O2 concentrations were measured throughout the growth stages of Naegleria gruberi in agitated culture in a complex medium. Biphasic logarithmic growth occurred during the intial 83 hr of growth and the mean generation time was 7.0 hr and 19 hr during initial and secondary log growth stages, respectively. The maximum yield was 5 X 10(6) amebae/ml. The pH rose rapidly (1 pH unit) during the secondary log growth phase (52-83 hr) and continued into the stationary growth phase (83-120 hr). Dry weight, total protein, carbohydrate, and RNA per ameba increased just before the secondary log growth phase. RNA increase 31% to 35% per ameba at the end of each phase of log growth. DNA increased approximately 2-fold throughout the different growth phases. Average cell size increased 90% during biphasic log growth then decreased during stationary phase. O2 tension decreased from 100% to 18% of saturation during the biphasic growth phase, then increased during stationary growth to near 100% saturation. Glucose and total carbohydrate assays showed little utilization of those substrates throughout the growth stages. Naegleria gruberi presumably has a predominantly aerobic metabolism, also its metabolism may change during the different growth phases.
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27
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Ryter A, Bowers B. Localization of acid phosphatase in Acanthamoeba castellanii with light and electron microscopy during growth and after phagocytosis. JOURNAL OF ULTRASTRUCTURE RESEARCH 1976; 57:309-21. [PMID: 1003596 DOI: 10.1016/s0022-5320(76)80119-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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28
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Martin SM, Byers TJ. Acid hydrolase activity during growth and encystment in Acanthamoeba castellanii. THE JOURNAL OF PROTOZOOLOGY 1976; 23:608-13. [PMID: 187746 DOI: 10.1111/j.1550-7408.1976.tb03851.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The activity and sedimentation of acid phosphatase (APase), acid deoxyribonuclease (DNase), and acid ribonuclease (RNase) were investigated throughout growth and encystment in Acanthamoeba castellanii. The activities/mg protein of all 3 hydrolases are high in young cultures and decrease to constant levels in postlog cells. The RNase activity/ameba decreases 50% during growth, whereas the activity/cell of both APase and DNase remains constant. The percent sedimentation at 20,000 g of all 3 enzymes gradually increases from about 40% in midlog to a plateau of 80% in postlog cells. During encystment, the sedimentation behavior of RNase differs from that of APase and DNase. Encystment is characterized by a differential decrease in the activity/cell of the 3 hydrolases, with RNase decreasing most rapidly and APase least rapidly. APase is unique in that a transient increase of its specific activity is noted during encystment, even though its activity/cell is decreasing.
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Larochelle J, Gagnon A. Osmoregulation in Acanthamoeba castellanii—II. Variations of the concentrations of some intracellular ions. ACTA ACUST UNITED AC 1976. [DOI: 10.1016/s0300-9629(76)80111-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Todd SR, Kitching JA. Cultivation of Acanthamoeba castellanii, Neff Strain, at high hydrostatic pressures. THE JOURNAL OF PROTOZOOLOGY 1975; 22:105-6. [PMID: 1117431 DOI: 10.1111/j.1550-7408.1975.tb00950.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Log-phase cultures of Acanthamoeba castellanii, Neff strain, have been maintained at elevated hydrostatic pressures over periods of several days and the population has been recounted at the end of the experimental period. A pressure of 2,000 psi (136 atm) depressed growth of the population, but was quickly reversed on release. A pressure of 4,000 psi (272 atm) severly depressed population growth, and any increase was slight and short-lasting at 5,000 psi (340 atm). Growth of the population was resumed only after an interval of 1 or more days after release.
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Polyadenylsäure—enthaltende RNA und genaktivitätsmuster während der entwicklung von Acanthamoeba castellanii. ACTA ACUST UNITED AC 1974. [DOI: 10.1016/0005-2787(74)90197-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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32
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Jantzen H. [Development of Acanthamoeba castellanii into a cyst with and without modification of gene activity pattern]. THE JOURNAL OF PROTOZOOLOGY 1974; 21:791-5. [PMID: 4449098 DOI: 10.1111/j.1550-7408.1974.tb03753.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Prescott LM, Lottman JK, Vance PL. Carbohydrate metabolism in Acanthamoeba castellanii. II. Carbon dioxide fixation reactions. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1974; 48:205-9. [PMID: 4151330 DOI: 10.1016/0305-0491(74)90196-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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34
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Gessat M, Jantzen H. [The role of adenosine-3',5'-monophosphate in the development of Acanthamoeba castellanii (author's transl)]. Arch Microbiol 1974; 99:155-66. [PMID: 4368284 DOI: 10.1007/bf00696231] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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McMillen J, Nazario M, Jensen T. Changes in transfer ribonucleic acids accompanying encystment in Acanthamoeba castellanii. J Bacteriol 1974; 117:242-51. [PMID: 4808904 PMCID: PMC246550 DOI: 10.1128/jb.117.1.242-251.1974] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Transfer ribonucleic acid (tRNA) from exponentially growing cells (trophozoites) and from precysts of Acanthamoeba castellanii were examined by reversed-phase column (RPC-2) chromatography. This system gave excellent resolution of isoaccepting species of tRNA. The tRNAs for 12 amino acids were studied. A comparison of trophozoite and precyst tRNA elution profiles revealed no apparent differences in the number of isoaccepting species of alanyl-, arginyl-, asparaginyl-, glycyl-, leucyl-, lysyl-, methionyl-, phenylalanyl-, tryptophanyl-, or valyl-tRNAs. Seryl-tRNAs from trophozoites were eluted as three components, whereas precyst seryl-tRNAs were eluted as only two components. Precharged trophozoite and precyst isoleucyl-tRNAs were both eluted as single components; however, post-chromatography charging of trophozoite tRNA resulted in three components of activity for tRNA(Ile) and only one component for precyst tRNA(Ile). None of the observed changes could be attributed to differences in synthetases or to the presence of altered tRNA lacking the CCA terminus or partially degraded by nucleases. The possible significance of these observations is discussed.
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Jantzen H. [The adenosinephosphate system during growth and development of Acanthamoeba castellanii (author's transl)]. Arch Microbiol 1974; 101:391-9. [PMID: 4455132 DOI: 10.1007/bf00455955] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Evans DA. Growth phase and the number of phosphorylation sites in the mitochondrial electron transport chain of Acanthamoeba castellanii. THE JOURNAL OF PROTOZOOLOGY 1973; 20:336-8. [PMID: 4350907 DOI: 10.1111/j.1550-7408.1973.tb00890.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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38
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Stevens AR, Pachler PF. RNA synthesis and turnover during density-inhibited growth and encystment of Acanthamoeba castellanii. J Cell Biol 1973; 57:525-37. [PMID: 4696550 PMCID: PMC2108987 DOI: 10.1083/jcb.57.2.525] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Alterations in transcription that precede and accompany encystment (E) of suspension grown A. castellanii have been investigated. Comparative studies were performed on cells undergoing spontaneous E in high density stationary phase cultures or after experimental induction of E at low cell densities by deprivation of nutrients in exponential growth. Onset of growth deceleration at high cell densities was accompanied by an increase in the cellular RNA. The maximum RNA content occurred in cells at stationary phase and subsequently declined with the appearance of cysts in the cultures. On the contrary, the RNA content in cells whose growth was immediately terminated by experimental E induction remained at a constant exponential level through 5 h postinduction and then began to decline shortly before the appearance of cysts. The mature cyst formed in stationary phase cultures and after experimental E induction contained an equivalent amount of RNA ( approximately 50% of the exponential value). Comparison of the kinetics of [(3)H]uridine incorporation demonstrated that there was an abrupt reduction in the rate of uridine incorporation into RNA with onset of growth deceleration or after growth termination in experimental E induction. The reduced incorporation of uridine into RNA could not be attributed to to a reduced uptake of the isotope by the cells or an altered capacity of the cells to phosphorylate uridine. Uridine continued to be incorporated into RNA at a reduced rate in cells throughout growth deceleration, in stationary phase, and up to 12 h postexperimental induction. Considered together, these results indicate that a buildup in RNA is not necessary for induction of encystment in acanthamoeba. The accumulated RNA in stationary phase cells appears to be due to the greater reduction in the growth rate than in transcription and the absence of RNA turnover in cells during growth deceleration. Initiation of RNA turnover appears to accompany growth termination and induction of E. The results further demonstrate that the regulation of the rate of transcription is closely coordinated with the control of growth and encystment in acanthamoeba.
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Fouquet H. [Properties of the mitochondrial electron transport system of Acanthamoeba castellanii Neff. I. Effect of inhibitors on various acceptor systems tested by means of a modified Thunberg technic]. THE JOURNAL OF PROTOZOOLOGY 1973; 20:328-31. [PMID: 4145409 DOI: 10.1111/j.1550-7408.1973.tb00888.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Rudick VL, Weisman RA. DNA-dependent RNA polymerase from trophozoites and cysts of Acanthamoeba castellanii. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 299:91-102. [PMID: 4701078 DOI: 10.1016/0005-2787(73)90400-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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41
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�nderung des Genaktivit�tsmusters w�hrend der Entwicklung von Acanthamoeba castellanii. Arch Microbiol 1973. [DOI: 10.1007/bf00424759] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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42
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Rastogi AK, Sagar P, Agarwala SC. Changes in the levels of some macromolecules and certain enzyme activities in excysting Schizopyrenus russelli. THE JOURNAL OF PROTOZOOLOGY 1971; 18:506-9. [PMID: 5132322 DOI: 10.1111/j.1550-7408.1971.tb03363.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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43
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Abstract
Light from 350 to 680 nm at intensities up to 1.62 x 10(5) ergs per sec per cm(2) slowed exponential growth and lowered the maximum yield in axenic cultures of Acanthamoeba castellanii. Photoinhibition was a linear function of light intensity up to 1.25 x 10(5) ergs per sec per cm(2). At higher intensities, growth was too slow to be measured accurately. A photochemical change occurring in the growth medium on irradiation was a function of light dosage and not intensity per se. Light in dosages which appreciably changed the growth-supporting properties of the medium exceeded the dosages received by exponentially growing cultures during irradiation. Consequently, photoinhibition of growth was attributed to a direct effect of light on the amoebae, not to photodegradation of the medium. The growth-supporting properties of irradiated media could be restored by the addition of yeast extract and Proteose peptone. The reduced growth rate in the light was not due to cyst formation or induction of multinuclearity. Light affected the amoebae either through absorption by intracellular pigment(s) or through binding to the amoebae of a photosensitizing compound in the medium.
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