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Eric Wieschaus - One of the best experts on this subject based on the ideXlab platform.
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pulsed contractions of an actin myosin network drive apical constriction
Nature, 2009Co-Authors: Adam C Martin, Matthias Kaschube, Eric WieschausAbstract:During development, changes in individual cell shape drive the overall organization of organs and tissues. Now a study of the dynamics of cell behaviour during fruit fly development reveals a previously unknown ratchet-like mechanism that drives cell shape change. Gastrulation in the Drosophila embryo involves the apical constriction of ventral cells, which induces a ventral furrow and invagination of the mesoderm. This new work shows that the apical constriction of ventral cells is pulsed: repeated Constrictions are interrupted by pauses in which the constricted state of the cells in maintained. These pulses are powered by actin–myosin contractions and are dependent on the expression of a transcription factor Snail, whereas the constricted state is stabilized by another transcription factor, Twist. During gastrulation in Drosophila embryo, there is apical constriction of ventral cells, which results in formation of a ventral furrow and invagination of the mesoderm. This study reports a mechanism for this process and shows that apical constriction of ventral cells is pulsed. These pulses are powered by the actin–myosin contractions and are dependent on the expression of a transcription factor, Snail, whereas the constricted state is stabilized by the transcription factor Twist. Apical constriction facilitates epithelial sheet bending and invagination during morphogenesis1,2. Apical constriction is conventionally thought to be driven by the continuous purse-string-like contraction of a circumferential actin and non-muscle myosin-II (myosin) belt underlying adherens junctions3,4,5,6,7. However, it is unclear whether other force-generating mechanisms can drive this process. Here we show, with the use of real-time imaging and quantitative image analysis of Drosophila gastrulation, that the apical constriction of ventral furrow cells is pulsed. Repeated Constrictions, which are asynchronous between neighbouring cells, are interrupted by pauses in which the constricted state of the cell apex is maintained. In contrast to the purse-string model, constriction pulses are powered by actin–myosin network contractions that occur at the medial apical cortex and pull discrete adherens junction sites inwards. The transcription factors Twist and Snail differentially regulate pulsed constriction. Expression of snail initiates actin–myosin network contractions, whereas expression of twist stabilizes the constricted state of the cell apex. Our results suggest a new model for apical constriction in which a cortical actin–myosin cytoskeleton functions as a developmentally controlled subcellular ratchet to reduce apical area incrementally.
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pulsed contractions of an actin myosin network drive apical constriction
Nature, 2009Co-Authors: Adam C Martin, Matthias Kaschube, Eric WieschausAbstract:Apical constriction facilitates epithelial sheet bending and invagination during morphogenesis. Apical constriction is conventionally thought to be driven by the continuous purse-string-like contraction of a circumferential actin and non-muscle myosin-II (myosin) belt underlying adherens junctions. However, it is unclear whether other force-generating mechanisms can drive this process. Here we show, with the use of real-time imaging and quantitative image analysis of Drosophila gastrulation, that the apical constriction of ventral furrow cells is pulsed. Repeated Constrictions, which are asynchronous between neighbouring cells, are interrupted by pauses in which the constricted state of the cell apex is maintained. In contrast to the purse-string model, constriction pulses are powered by actin-myosin network contractions that occur at the medial apical cortex and pull discrete adherens junction sites inwards. The transcription factors Twist and Snail differentially regulate pulsed constriction. Expression of snail initiates actin-myosin network contractions, whereas expression of twist stabilizes the constricted state of the cell apex. Our results suggest a new model for apical constriction in which a cortical actin-myosin cytoskeleton functions as a developmentally controlled subcellular ratchet to reduce apical area incrementally.
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pulsed contractions of an actin myosin network drive apical constriction
Nature, 2009Co-Authors: Adam C Marti, Matthias Kaschube, Eric WieschausAbstract:Apical constriction facilitates epithelial sheet bending and invagination during morphogenesis. Apical constriction is conventionally thought to be driven by the continuous purse-string-like contraction of a circumferential actin and non-muscle myosin-II (myosin) belt underlying adherens junctions. However, it is unclear whether other force-generating mechanisms can drive this process. Here we show, with the use of real-time imaging and quantitative image analysis of Drosophila gastrulation, that the apical constriction of ventral furrow cells is pulsed. Repeated Constrictions, which are asynchronous between neighbouring cells, are interrupted by pauses in which the constricted state of the cell apex is maintained. In contrast to the purse-string model, constriction pulses are powered by actin-myosin network contractions that occur at the medial apical cortex and pull discrete adherens junction sites inwards. The transcription factors Twist and Snail differentially regulate pulsed constriction. Expression of snail initiates actin-myosin network contractions, whereas expression of twist stabilizes the constricted state of the cell apex. Our results suggest a new model for apical constriction in which a cortical actin-myosin cytoskeleton functions as a developmentally controlled subcellular ratchet to reduce apical area incrementally.
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a putative cell signal encoded by the folded gastrulation gene coordinates cell shape changes during drosophila gastrulation
Cell, 1994Co-Authors: Michael Costa, Ellen T Wilson, Eric WieschausAbstract:Abstract The folded gastrulation (fog) gene is required during Drosophila gastrulation for two morphogenetic movements, formation of the ventral furrow and invagination of the posterior midgut primordium. fog coordinates cell shape changes during these invaginations by inducing apical constriction of cells in spatially and temporally defined manners. fog is expressed in the invagination primordia in a pattern that precisely precedes the pattern of Constrictions. Overexpression of fog in the dorsoanterior region of the embryo induces ectopic Constrictions, indicating localization of fog transcripts may define domains of cell shape changes. fog encodes a novel protein with a putative signal sequence but no potential transmembrane domains. We suggest fog functions as a secreted signal that activates the G protein α subunit encoded by concertina in neighboring cells. Our analyses indicate that cell-cell communication ensures the rapid, orderly progression of constriction initiations from the middle of invagination primordia out toward the margins.
Brian Kirby - One of the best experts on this subject based on the ideXlab platform.
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continuous flow particle separation by 3d insulative dielectrophoresis using coherently shaped dc biased ac electric fields
Analytical Chemistry, 2007Co-Authors: Benjamin G Hawkins, Ezekiel A Smith, Yusef Syed, Brian KirbyAbstract:We present the development of a continuous-flow, “dielectrophoretic spectrometer” based on insulative DEP techniques and three-dimensional geometric design. Hot-embossed thermoplastic devices allow for high-throughput analysis and geometric control of electric fields via ridged microstructures patterned in a high width-to-depth aspect ratio (250:1) channel. We manipulate particles with dc-biased, ac electric fields and generate continuous-output streams of particles with a transverse outlet position specified by linear and nonlinear particle mobilities. We show, with simulation and experiment, that characteristic shape factors can be defined that capture the effects of Constrictions in channel depth and that modulating the angle of these Constrictions changes the resulting local DEP force. Microdevices are fabricated with an insulative constriction in channel depth, whose angle of incidence with the direction of flow varies continuously across the channel width. The resulting electric field gradients enab...
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continuous flow particle separation by 3d insulative dielectrophoresis using coherently shaped dc biased ac electric fields
Analytical Chemistry, 2007Co-Authors: Benjamin G Hawkins, Ezekiel A Smith, Yusef Syed, Brian KirbyAbstract:We present the development of a continuous-flow, "dielectrophoretic spectrometer" based on insulative DEP techniques and three-dimensional geometric design. Hot-embossed thermoplastic devices allow for high-throughput analysis and geometric control of electric fields via ridged microstructures patterned in a high width-to-depth aspect ratio (250:1) channel. We manipulate particles with dc-biased, ac electric fields and generate continuous-output streams of particles with a transverse outlet position specified by linear and nonlinear particle mobilities. We show, with simulation and experiment, that characteristic shape factors can be defined that capture the effects of Constrictions in channel depth and that modulating the angle of these Constrictions changes the resulting local DEP force. Microdevices are fabricated with an insulative constriction in channel depth, whose angle of incidence with the direction of flow varies continuously across the channel width. The resulting electric field gradients enable demonstration of a dielectrophoretic spectrometer that separates particles and controls their transverse channel position.
Benjamin G Hawkins - One of the best experts on this subject based on the ideXlab platform.
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continuous flow particle separation by 3d insulative dielectrophoresis using coherently shaped dc biased ac electric fields
Analytical Chemistry, 2007Co-Authors: Benjamin G Hawkins, Ezekiel A Smith, Yusef Syed, Brian KirbyAbstract:We present the development of a continuous-flow, “dielectrophoretic spectrometer” based on insulative DEP techniques and three-dimensional geometric design. Hot-embossed thermoplastic devices allow for high-throughput analysis and geometric control of electric fields via ridged microstructures patterned in a high width-to-depth aspect ratio (250:1) channel. We manipulate particles with dc-biased, ac electric fields and generate continuous-output streams of particles with a transverse outlet position specified by linear and nonlinear particle mobilities. We show, with simulation and experiment, that characteristic shape factors can be defined that capture the effects of Constrictions in channel depth and that modulating the angle of these Constrictions changes the resulting local DEP force. Microdevices are fabricated with an insulative constriction in channel depth, whose angle of incidence with the direction of flow varies continuously across the channel width. The resulting electric field gradients enab...
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continuous flow particle separation by 3d insulative dielectrophoresis using coherently shaped dc biased ac electric fields
Analytical Chemistry, 2007Co-Authors: Benjamin G Hawkins, Ezekiel A Smith, Yusef Syed, Brian KirbyAbstract:We present the development of a continuous-flow, "dielectrophoretic spectrometer" based on insulative DEP techniques and three-dimensional geometric design. Hot-embossed thermoplastic devices allow for high-throughput analysis and geometric control of electric fields via ridged microstructures patterned in a high width-to-depth aspect ratio (250:1) channel. We manipulate particles with dc-biased, ac electric fields and generate continuous-output streams of particles with a transverse outlet position specified by linear and nonlinear particle mobilities. We show, with simulation and experiment, that characteristic shape factors can be defined that capture the effects of Constrictions in channel depth and that modulating the angle of these Constrictions changes the resulting local DEP force. Microdevices are fabricated with an insulative constriction in channel depth, whose angle of incidence with the direction of flow varies continuously across the channel width. The resulting electric field gradients enable demonstration of a dielectrophoretic spectrometer that separates particles and controls their transverse channel position.
Matthias Kaschube - One of the best experts on this subject based on the ideXlab platform.
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pulsed contractions of an actin myosin network drive apical constriction
Nature, 2009Co-Authors: Adam C Martin, Matthias Kaschube, Eric WieschausAbstract:During development, changes in individual cell shape drive the overall organization of organs and tissues. Now a study of the dynamics of cell behaviour during fruit fly development reveals a previously unknown ratchet-like mechanism that drives cell shape change. Gastrulation in the Drosophila embryo involves the apical constriction of ventral cells, which induces a ventral furrow and invagination of the mesoderm. This new work shows that the apical constriction of ventral cells is pulsed: repeated Constrictions are interrupted by pauses in which the constricted state of the cells in maintained. These pulses are powered by actin–myosin contractions and are dependent on the expression of a transcription factor Snail, whereas the constricted state is stabilized by another transcription factor, Twist. During gastrulation in Drosophila embryo, there is apical constriction of ventral cells, which results in formation of a ventral furrow and invagination of the mesoderm. This study reports a mechanism for this process and shows that apical constriction of ventral cells is pulsed. These pulses are powered by the actin–myosin contractions and are dependent on the expression of a transcription factor, Snail, whereas the constricted state is stabilized by the transcription factor Twist. Apical constriction facilitates epithelial sheet bending and invagination during morphogenesis1,2. Apical constriction is conventionally thought to be driven by the continuous purse-string-like contraction of a circumferential actin and non-muscle myosin-II (myosin) belt underlying adherens junctions3,4,5,6,7. However, it is unclear whether other force-generating mechanisms can drive this process. Here we show, with the use of real-time imaging and quantitative image analysis of Drosophila gastrulation, that the apical constriction of ventral furrow cells is pulsed. Repeated Constrictions, which are asynchronous between neighbouring cells, are interrupted by pauses in which the constricted state of the cell apex is maintained. In contrast to the purse-string model, constriction pulses are powered by actin–myosin network contractions that occur at the medial apical cortex and pull discrete adherens junction sites inwards. The transcription factors Twist and Snail differentially regulate pulsed constriction. Expression of snail initiates actin–myosin network contractions, whereas expression of twist stabilizes the constricted state of the cell apex. Our results suggest a new model for apical constriction in which a cortical actin–myosin cytoskeleton functions as a developmentally controlled subcellular ratchet to reduce apical area incrementally.
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pulsed contractions of an actin myosin network drive apical constriction
Nature, 2009Co-Authors: Adam C Martin, Matthias Kaschube, Eric WieschausAbstract:Apical constriction facilitates epithelial sheet bending and invagination during morphogenesis. Apical constriction is conventionally thought to be driven by the continuous purse-string-like contraction of a circumferential actin and non-muscle myosin-II (myosin) belt underlying adherens junctions. However, it is unclear whether other force-generating mechanisms can drive this process. Here we show, with the use of real-time imaging and quantitative image analysis of Drosophila gastrulation, that the apical constriction of ventral furrow cells is pulsed. Repeated Constrictions, which are asynchronous between neighbouring cells, are interrupted by pauses in which the constricted state of the cell apex is maintained. In contrast to the purse-string model, constriction pulses are powered by actin-myosin network contractions that occur at the medial apical cortex and pull discrete adherens junction sites inwards. The transcription factors Twist and Snail differentially regulate pulsed constriction. Expression of snail initiates actin-myosin network contractions, whereas expression of twist stabilizes the constricted state of the cell apex. Our results suggest a new model for apical constriction in which a cortical actin-myosin cytoskeleton functions as a developmentally controlled subcellular ratchet to reduce apical area incrementally.
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pulsed contractions of an actin myosin network drive apical constriction
Nature, 2009Co-Authors: Adam C Marti, Matthias Kaschube, Eric WieschausAbstract:Apical constriction facilitates epithelial sheet bending and invagination during morphogenesis. Apical constriction is conventionally thought to be driven by the continuous purse-string-like contraction of a circumferential actin and non-muscle myosin-II (myosin) belt underlying adherens junctions. However, it is unclear whether other force-generating mechanisms can drive this process. Here we show, with the use of real-time imaging and quantitative image analysis of Drosophila gastrulation, that the apical constriction of ventral furrow cells is pulsed. Repeated Constrictions, which are asynchronous between neighbouring cells, are interrupted by pauses in which the constricted state of the cell apex is maintained. In contrast to the purse-string model, constriction pulses are powered by actin-myosin network contractions that occur at the medial apical cortex and pull discrete adherens junction sites inwards. The transcription factors Twist and Snail differentially regulate pulsed constriction. Expression of snail initiates actin-myosin network contractions, whereas expression of twist stabilizes the constricted state of the cell apex. Our results suggest a new model for apical constriction in which a cortical actin-myosin cytoskeleton functions as a developmentally controlled subcellular ratchet to reduce apical area incrementally.
Adam C Martin - One of the best experts on this subject based on the ideXlab platform.
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pulsed contractions of an actin myosin network drive apical constriction
Nature, 2009Co-Authors: Adam C Martin, Matthias Kaschube, Eric WieschausAbstract:During development, changes in individual cell shape drive the overall organization of organs and tissues. Now a study of the dynamics of cell behaviour during fruit fly development reveals a previously unknown ratchet-like mechanism that drives cell shape change. Gastrulation in the Drosophila embryo involves the apical constriction of ventral cells, which induces a ventral furrow and invagination of the mesoderm. This new work shows that the apical constriction of ventral cells is pulsed: repeated Constrictions are interrupted by pauses in which the constricted state of the cells in maintained. These pulses are powered by actin–myosin contractions and are dependent on the expression of a transcription factor Snail, whereas the constricted state is stabilized by another transcription factor, Twist. During gastrulation in Drosophila embryo, there is apical constriction of ventral cells, which results in formation of a ventral furrow and invagination of the mesoderm. This study reports a mechanism for this process and shows that apical constriction of ventral cells is pulsed. These pulses are powered by the actin–myosin contractions and are dependent on the expression of a transcription factor, Snail, whereas the constricted state is stabilized by the transcription factor Twist. Apical constriction facilitates epithelial sheet bending and invagination during morphogenesis1,2. Apical constriction is conventionally thought to be driven by the continuous purse-string-like contraction of a circumferential actin and non-muscle myosin-II (myosin) belt underlying adherens junctions3,4,5,6,7. However, it is unclear whether other force-generating mechanisms can drive this process. Here we show, with the use of real-time imaging and quantitative image analysis of Drosophila gastrulation, that the apical constriction of ventral furrow cells is pulsed. Repeated Constrictions, which are asynchronous between neighbouring cells, are interrupted by pauses in which the constricted state of the cell apex is maintained. In contrast to the purse-string model, constriction pulses are powered by actin–myosin network contractions that occur at the medial apical cortex and pull discrete adherens junction sites inwards. The transcription factors Twist and Snail differentially regulate pulsed constriction. Expression of snail initiates actin–myosin network contractions, whereas expression of twist stabilizes the constricted state of the cell apex. Our results suggest a new model for apical constriction in which a cortical actin–myosin cytoskeleton functions as a developmentally controlled subcellular ratchet to reduce apical area incrementally.
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pulsed contractions of an actin myosin network drive apical constriction
Nature, 2009Co-Authors: Adam C Martin, Matthias Kaschube, Eric WieschausAbstract:Apical constriction facilitates epithelial sheet bending and invagination during morphogenesis. Apical constriction is conventionally thought to be driven by the continuous purse-string-like contraction of a circumferential actin and non-muscle myosin-II (myosin) belt underlying adherens junctions. However, it is unclear whether other force-generating mechanisms can drive this process. Here we show, with the use of real-time imaging and quantitative image analysis of Drosophila gastrulation, that the apical constriction of ventral furrow cells is pulsed. Repeated Constrictions, which are asynchronous between neighbouring cells, are interrupted by pauses in which the constricted state of the cell apex is maintained. In contrast to the purse-string model, constriction pulses are powered by actin-myosin network contractions that occur at the medial apical cortex and pull discrete adherens junction sites inwards. The transcription factors Twist and Snail differentially regulate pulsed constriction. Expression of snail initiates actin-myosin network contractions, whereas expression of twist stabilizes the constricted state of the cell apex. Our results suggest a new model for apical constriction in which a cortical actin-myosin cytoskeleton functions as a developmentally controlled subcellular ratchet to reduce apical area incrementally.