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Abstract
An in vitro teratogen assay has been developed that uses Drosophila embryo cell cultures. The endpoints selected in assessing the teratogenic potential of any agent (physical or chemical) involves detection of interference with normal muscle and/or neuron differentiation, induction of heat stock (stress) proteins, and inhibition of normal neurotransmitter levels. Current studies involve use of reporter gene technology (protein fusions) to identify teratogenicity. Results so far suggest that the Drosophila assay is capable of accurately establishing if a particular agent tested can act as a teratogen by a variety of appropriate endpoints (morphological, biochemical, molecular). Furthermore, this assay can be used not only as a teratogen screen, but also in mechanistic studies of abnormal development, gene involvement in teratogenic resistance, and the possible role of heat shock proteins in preventing birth defects.
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Affiliation(s)
- Nicole Bournias-Vardiabasis
- Department of Biology, California State University, San Bernadino, CA 92407, USA and Division of Neurosciences, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
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2
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Lüer K, Technau GM. Single cell cultures of Drosophila neuroectodermal and mesectodermal central nervous system progenitors reveal different degrees of developmental autonomy. Neural Dev 2009; 4:30. [PMID: 19650920 PMCID: PMC2736940 DOI: 10.1186/1749-8104-4-30] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Accepted: 08/03/2009] [Indexed: 11/10/2022] Open
Abstract
Background The Drosophila embryonic central nervous system (CNS) develops from two sets of progenitor cells, neuroblasts and ventral midline progenitors, which behave differently in many respects. Neuroblasts derive from the neurogenic region of the ectoderm and form the lateral parts of the CNS. Ventral midline precursors are formed by two rows of mesectodermal cells and build the CNS midline. There is plenty of evidence that individual identities are conferred to precursor cells by positional information in the ectoderm. It is unclear, however, how far the precursors can maintain their identities and developmental properties in the absence of normal external signals. Results To separate the respective contributions of autonomous properties versus extrinsic signals during their further development, we isolated individual midline precursors and neuroectodermal precursors at the pre-mitotic gastrula stage, traced their development in vitro, and analyzed the characteristics of their lineages in comparison with those described for the embryo. Although individually cultured mesectodermal cells exhibit basic characteristics of CNS midline progenitors, the clones produced by these progenitors differ from their in situ counterparts with regard to cell numbers, expression of molecular markers, and the separation of neuronal and glial fate. In contrast, clones derived from individually cultured precursors taken from specific dorsoventral zones of the neuroectoderm develop striking similarities to the lineages of neuroblasts that normally delaminate from these zones and develop in situ. Conclusion This in vitro analysis allows for the first time a comparison of the developmental capacities in situ and in vitro of individual neural precursors of defined spatial and temporal origin. The data reveal that cells isolated at the pre-mitotic and pre-delamination stage express characteristics of the progenitor type appropriate to their site of origin in the embryo. However, presumptive neuroblasts, once specified in the neuroectoderm, exhibit a higher degree of autonomy regarding generation of their lineages compared to mesectodermal midline progenitors.
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Affiliation(s)
- Karin Lüer
- Institute of Genetics, University of Mainz, Germany.
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Tucker JB, Mackie JB, Cottam DM, Rogers-Bald MM, Macintyre J, Scarborough JA, Milner MJ. Positioning and capture of cell surface-associated microtubules in epithelial tendon cells that differentiate in primary embryonic Drosophila cell cultures. ACTA ACUST UNITED AC 2004; 57:175-85. [PMID: 14743350 DOI: 10.1002/cm.10167] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Using primary embryonic Drosophila cell cultures, we have investigated the assembly of transcellular microtubule bundles in epidermal tendon cells. Muscles attach to the tendon cells of previously undescribed epidermal balls that form shortly after culture initiation. Basal capture of microtubule ends in cultured tendon cells is confined to discrete sites that occupy a relatively small proportion of the basal cell surface. These capturing sites are associated with hemiadherens junctions that link the ends of muscle cells to tendon cell bases. In vivo, muscle attachment and microtubule capture occur across the entire cell base. The cultured tendon cells reveal that the basal ends of their microtubules can be precisely targeted to small, pre-existing, structurally well-defined cortical capturing sites. However, a search and capture targeting procedure, such as that undertaken by kinetochore microtubules, cannot fully account for the precision of microtubule capture and positioning in tendon cells. We propose that cross-linkage of microtubules is also required to zip them into apicobasally oriented alignment, progressing from captured basal plus ends to apical minus ends. This involves repositioning of apical minus ends before they become anchored to an apical set of hemiadherens junctions. The proposal is consistent with our finding that hemiadherens junctions assemble at tendon cell bases before they do so at cell apices in both cultures and embryos. It is argued that control of microtubule positioning in the challenging spatial situations found in vitro involves the same procedures as those that operate in vivo.
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Affiliation(s)
- John B Tucker
- School of Biology, University of St Andrews, St Andrews, Fife, Scotland.
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Doberstein SK, Fetter RD, Mehta AY, Goodman CS. Genetic analysis of myoblast fusion: blown fuse is required for progression beyond the prefusion complex. J Cell Biol 1997; 136:1249-61. [PMID: 9087441 PMCID: PMC2132517 DOI: 10.1083/jcb.136.6.1249] [Citation(s) in RCA: 174] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The events of myoblast fusion in Drosophila are dissected here by combining genetic analysis with light and electron microscopy. We describe a new and essential intermediate step in the process, the formation of a prefusion complex consisting of "paired vesicles." These pairs of vesicles from different cells align with each other across apposed plasma membranes. This prefusion complex resolves into dense membrane plaques between apposed cells; these cells then establish cytoplasmic continuity by fusion of small areas of plasma membrane followed by vesiculation of apposed membranes. Different steps in this process are specifically blocked by mutations in four genes required for myoblast fusion. One of these genes, blown fuse, encodes a novel cytoplasmic protein expressed in unfused myoblasts that is essential for progression beyond the prefusion complex stage.
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Affiliation(s)
- S K Doberstein
- Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA
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5
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Bernstein SI, O'Donnell PT, Cripps RM. Molecular genetic analysis of muscle development, structure, and function in Drosophila. INTERNATIONAL REVIEW OF CYTOLOGY 1993; 143:63-152. [PMID: 8449665 DOI: 10.1016/s0074-7696(08)61874-4] [Citation(s) in RCA: 145] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- S I Bernstein
- Department of Biology, San Diego State University, California 92182
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Bermudez I, Lees G, Botham RP, Beadle DJ. Myogenesis and neuromuscular junction formation in cultures of Periplaneta americana myoblasts and neurones. Dev Biol 1986. [DOI: 10.1016/0012-1606(86)90147-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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7
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Bournias-Vardiabasis N, Buzin CH. Developmental effects of chemicals and the heat shock response in Drosophila cells. TERATOGENESIS, CARCINOGENESIS, AND MUTAGENESIS 1986; 6:523-36. [PMID: 2881367 DOI: 10.1002/tcm.1770060606] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Exposure of prokaryotic and eukaryotic cells to heat shock (hyperthermia) or to a number of diverse environmental stresses such as teratogens, anoxia, and inhibitors of oxidative phosphorylation results in the enhanced synthesis of a number of proteins which have been previously referred to as heat shock proteins (hsps). More recently, in view of the diverse types of agents that can induce these proteins, they have also been referred to as stress proteins. This phenomenon is one of the most basic regulatory mechanisms in living organisms. Exposure of Drosophila embryos, larvae, or pupae to these types of stresses also results in a variety of developmental abnormalities in the ensuing adult. Although the function(s) of these heat shock proteins has yet to be determined, they are widely thought to play an important role in cell survival and protection following some types of environmental stress. In our laboratory, we have developed an in vitro assay for detecting agents that act as teratogens, utilizing Drosophila embryonic cultures. Drosophila embryonic cells differentiate in vitro to a number of functional cell types including myotubes and ganglia. A number of drugs that have been shown to act as teratogens in mammals have also been found to inhibit muscle and/or neuron differentiation in Drosophila embryonic cultures. We have examined, by two-dimensional gel electrophoresis, the effects of such teratogens on protein synthesis in Drosophila embryonic cells. Inhibition of muscle and/or neuron differentiation correlates well with the induction of two proteins of about 20 kilodaltons. These are identical to two of the heat shock proteins (hsp 23, 22) as shown by electrophoretic mobilities and peptide mapping by partial proteolysis. Heat shock and other treatments such as exposure to some of the metal ions and ether induces the entire set of seven major heat shock proteins in the Drosophila embryonic cells. Dose-response studies of several teratogens show a correlation between the degree of inhibition of differentiation and the level of induction of hsps. Since heat shock proteins have been suggested as possibly serving a protecting role, our present studies are aimed at identifying the role of hsps in teratogenesis and investigating the differential regulation of heat shock genes in response to different external stimuli.
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Bournias-Vardiabasis N, Teplitz RL, Chernoff GF, Seecof RL. Detection of teratogens in the Drosophila embryonic cell culture test: assay of 100 chemicals. TERATOLOGY 1983; 28:109-22. [PMID: 6635990 DOI: 10.1002/tera.1420280114] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
An in vitro assay of teratogenesis has been developed that utilizes Drosophila embryonic cell cultures. The endpoint selected in assessing the teratogenic potential of any substance involves detection of interference with normal muscle and/or neuron differentiation. In the validation phase of this project, 100 chemicals were tested. With drugs for which extensive reliable mammalian data are available, the results in the Drosophila assay equate rather favorably with those observed in animals and humans (i.e., a low percentage of false positives and false negatives has been obtained). In an effort to determine if strain differences exist and also to establish that the system shows a dose response, cultures from three wild-type Drosophila strains (Canton S, Canton S109, and Oregon R) were tested. Dose-response differences were observed when diethylstilbestrol, diphenylhydantoin, imipramine, testosterone, and tolbutamide were added to the cultures. These results suggest that the Drosophila assay, with further testing and refinements, might be capable of identifying agents of high teratogenic potential by their effect on neurons and muscle differentiation. Furthermore, sensitive strains might be used to study mechanisms of abnormal development and gene involvement in teratogenic resistance.
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Bournias-Vardiabasis N, Teplitz RL. Use of Drosophila embryo cell cultures as an in vitro teratogen assay. TERATOGENESIS, CARCINOGENESIS, AND MUTAGENESIS 1982; 2:333-41. [PMID: 6130633 DOI: 10.1002/1520-6866(1990)2:3/4<333::aid-tcm1770020315>3.0.co;2-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
An in vitro assay has been developed for detecting teratogens by adding them to primary cultures of embryonic Drosophila cells and analyzing the degree of change in cell differentiation and tissue formation. Cultures are scored by an automated image analysis system that counts the number of myotubes and ganglia in culture. A decrease in their number compared to controls is taken as an indication of teratogenicity. In the group of 100 drugs and chemicals examined thus far in this assay, a high correlation with known teratogenic activity has been obtained with few false-positives or false-negatives. Procedures also have been developed for testing metabolic products of ingested compounds for teratogenicity. Mice and rats are fed the particular agent to be tested, and their serum is then added to the differentiating culture. Preliminary trials with human serum from patients receiving chemotherapy have also been performed. With further testing, validation, and incorporation of a metabolic activation system, it is hoped that this assay can be used, along with a battery of other in vitro assays, as a screen for the large number of agents awaiting comprehensive testing of their teratogenic potential. We also see the use of this assay as means to gain further information on the basic biochemical and developmental aspects of teratogenesis.
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Buzin CH, Seecof RL. Developmental modulation of protein synthesis in Drosophila primary embryonic cell cultures. ACTA ACUST UNITED AC 1981. [DOI: 10.1002/dvg.1020020303] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Sang JH. Drosophila Cells and Cell Lines. ACTA ACUST UNITED AC 1981. [DOI: 10.1016/b978-0-12-007901-8.50011-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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12
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Tadkowski TM, McCann FV. Ultrastructure and electrical activity in developing heart cells (insect). Dev Biol 1980; 74:387-400. [PMID: 7371981 DOI: 10.1016/0012-1606(80)90440-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Fyrberg EA, Donady JJ. Actin Heterogeneity in primary embryonic culture cells from Drosophila melanogaster. Dev Biol 1979; 68:487-502. [PMID: 108158 DOI: 10.1016/0012-1606(79)90220-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Buzin CH, Dewhurst SA, Seecof RL. Temperature sensitivity of muscle and neuron differentiation in embryonic cell cultures from the Drosophila mutant, shibire. Dev Biol 1978; 66:442-56. [PMID: 100358 DOI: 10.1016/0012-1606(78)90250-6] [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: 12/13/2022]
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Dübendorfer A, Blumer A, Deàk II. Differentiation in vitro of larval and adult muscles from embryonic cells ofDrosophila. ACTA ACUST UNITED AC 1978; 184:233-249. [PMID: 28305038 DOI: 10.1007/bf00848256] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/1978] [Accepted: 02/24/1978] [Indexed: 11/28/2022]
Abstract
The differentiation of muscles in primary cultures of cells fromDrosophila melanogaster embryos was investigated. In early cultures, and in the absence of exogenous ecdysone, two main classes of muscle were found. Comparison, by light and electron microscopy, of one of these classes (the "myotube" class) with muscles from third instar larvae shows that this class corresponds to the muscles of the body wall of the larva. When α- or β-ecdysone is added to the cultures, these undergo a number of metamorphic changes. Most of the larval muscles disappear, and two new types of muscle form. Ultrastructural and light microscopic examination of these two types indicates that they correspond to the two classes of skeletal muscle (fibrillar and tubular) found in adult flies.
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Affiliation(s)
- Andreas Dübendorfer
- Zoologisches Institut der Universität Zürich, Künstlergasse 16, 8006, Zürich, Switzerland
| | - Annemarie Blumer
- Zoologisches Institut der Universität Zürich, Künstlergasse 16, 8006, Zürich, Switzerland
| | - Ilan Ivan Deàk
- Zoologisches Institut der Universität Zürich, Künstlergasse 16, 8006, Zürich, Switzerland
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Fyrberg E, James Donady J, Bernstein S. Isolation of myoblasts from primary mass cultures of embryonicDrosophila cells. ACTA ACUST UNITED AC 1977. [DOI: 10.1007/bf00920382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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