Mitotic domains reveal early commitment of cells in Drosophila embryos

Development ◽  
1989 ◽  
Vol 107 (1) ◽  
pp. 1-22 ◽  
Author(s):  
V.E. Foe
Keyword(s):  
Single Cell ◽  
Domain Boundary ◽  
Cell Sheet ◽  
Mirror Image ◽  
Fine Scale ◽  
Dorsal Midline ◽  
Specific Position ◽  
Synchronous Mitosis ◽  
Mitotic Synchrony ◽  
Drosophila Embryos

In embryos of Drosophila melanogaster all the nuclei in the syncytial egg divide with global synchrony during the first 13 mitotic cycles. But with cellularization in the 14th cycle, global mitotic synchrony ceases. Starting about one hour into the 14th interphase, at least 25 ‘mitotic domains’, which are clusters of cells united by locally synchronous mitosis, partition the embryo blastoderm surface into a complex fine-scale pattern. These mitotic domains, which are constant from one embryo to the next, fire in the same temporal sequence in every embryo. Some domains consist of a single cell cluster straddling the ventral or dorsal midline. Most consist of two separate cell clusters that occupy mirror-image positions on the bilaterally symmetric embryo. Others comprise a series of members present not only as bilateral pairs but also as metameric repeats. Thus a domain can consist of either one, two, or many (if metamerically reiterated) clusters of contiguous cells. Within each cluster, mitosis starts in a single cell or in a small number of interior cells then spreads wave-like, in all directions, until it stops at the domain boundary. Each domain occupies a specific position along the anteroposterior axis—as determined by the expression pattern of the engrailed protein, and along the dorsoventral axis—as determined by cell count from the ventral midline. The primordia of certain larval structures appear to consist solely of the cells of one specific mitotic domain. Moreover, cells in at least some mitotic domains share specific morphogenetic traits, distinct from those of cells in adjacent domains. These traits include cell shape, spindle orientation, and participation by all the cells of a domain in an invagination. The specialized behaviors of the various mitotic domains transform the monolayer cell sheet of the blastoderm into the multilayered gastrula. I conclude that the fine-scale partitioning of the newly cellularized embryo into mitotic domains is an early manifestation of the commitment of cells to specific developmental fates.

A single cell approach to problems of cell lineage and commitment during embryogenesis of Drosophila melanogaster

Development ◽  
1987 ◽  
Vol 100 (1) ◽  
pp. 1-12 ◽  
Author(s):  
G.M. Technau
Keyword(s):  
Drosophila Melanogaster ◽  
Single Cell ◽  
Cell Lineage ◽  
Cellular Level ◽  
Central Importance ◽  
Cell Level ◽  
Combined Application ◽  
A Cell ◽  
Pole Cells ◽  
Drosophila Embryos

The mechanisms leading to the commitment of a cell to a particular fate or to restrictions in its developmental potencies represent a problem of central importance in developmental biology. Both at the genetic and at the molecular level, studies addressing this topic using the fruitfly Drosophila melanogaster have advanced substantially, whereas, at the cellular level, experimental techniques have been most successfully applied to organisms composed of relatively large and accessible cells. The combined application of the different approaches to one system should improve our understanding of the process of commitment as a whole. Recently, a method has been devised to study cell lineage in Drosophila embryos at the single cell level. This method has been used to analyse the lineages, as well as the state of commitment of single cell progenitors from various ectodermal, mesodermal and endodermal anlagen and of the pole cells. The results obtained from a clonal analysis of wild-type larval structures are discussed in this review.

The quantification of single cell adhesion on functionalized surfaces for cell sheet engineering

Biomaterials ◽  
2010 ◽  
Vol 31 (25) ◽  
pp. 6436-6443 ◽  
Author(s):  
G. Weder ◽  
O. Guillaume-Gentil ◽  
N. Matthey ◽  
F. Montagne ◽  
H. Heinzelmann ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Single Cell ◽  
Cell Sheet ◽  
Cell Sheet Engineering ◽  
Functionalized Surfaces

scholarly journals Live cell imaging of metabolic heterogeneity by quantitative fluorescent ATP indicator protein, QUEEN-37C.

2021 ◽  
Author(s):  
Hideyuki Yaginuma ◽  
Yasushi Okada
Keyword(s):  
Single Cell ◽  
Mammalian Cells ◽  
Cell Sheet ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cell ◽  
Luciferase Assay ◽  
Atp Concentration ◽  
Cell Measurement ◽  
Positive Correlations ◽  
Metabolic Heterogeneity

Adenosine triphosphate (ATP) is often referred as the energy currency of the cell. Yet, non-invasive, real-time, and quantitative measurement of its concentration in living mammalian cells has been difficult. Here we report an improved fluorescent ATP indicator protein, QUEEN-37C, which is optimized for measuring ATP concentration in living mammalian cells. Absolute value of the ATP concentration can be estimated from the ratiometric fluorescence imaging, and its accuracy was verified by the luciferase assay. Since QUEEN-37C enables the single-cell measurement of ATP concentration, we can not only measure its mean but its distribution in the cell population, which revealed that the ATP concentration is tightly regulated in most cells. We also noted the positive correlations in the ATP concentration among adjacent cells in epithelial cell sheet and mouse embryonic stem cell colonies. Thus, QUEEN-37C would serve as a new tool for the investigation of the single cell heterogeneity of metabolic states.

Drosophila nonmuscle myosin II has multiple essential roles in imaginal disc and egg chamber morphogenesis

Development ◽  
1996 ◽  
Vol 122 (5) ◽  
pp. 1499-1511 ◽  
Author(s):  
K.A. Edwards ◽  
D.P. Kiehart
Keyword(s):  
Myosin Ii ◽  
Cell Sheet ◽  
Follicle Cell ◽  
Nonmuscle Myosin ◽  
Filamentous Actin ◽  
Nonmuscle Myosin Ii ◽  
Egg Chambers ◽  
Mutant Phenotypes ◽  
Shape Changes ◽  
Drosophila Embryos

Morphogenesis is characterized by orchestrated changes in the shape and position of individual cells. Many of these movements are thought to be powered by motor proteins. However, in metazoans, it is often difficult to match specific motors with the movements they drive. The nonmuscle myosin II heavy chain (MHC encoded by zipper is required for cell sheet movements in Drosophila embryos. To determine if myosin II is required for other processes, we examined the phenotypes of strong and weak larval lethal mutations in spaghetti squash (sqh), which encodes the nonmuscle myosin II regulatory light chain (RLC). sqh mutants can be rescued to adulthood by daily induction of a sqh cDNA transgene driven by the hsp70 promoter. By transiently ceasing induction of the cDNA, we depleted RLC at specific times during development. When RLC is transiently depleted in larvae, the resulting adult phenotypes demonstrate that RLC is required in a stage-specific fashion for proper development of eye and leg imaginal discs. When RLC is depleted in adult females, oogenesis is reversibly disrupted. Without RLC induction, developing egg chambers display a succession of phenotypes that demonstrate roles for myosin II in morphogenesis of the interfollicular stalks, three morphologically and mechanistically distinct types of follicle cell migration, and completion of nurse cell cytoplasm transport (dumping). Finally, we show that in sqh mutant tissues, MHC is abnormally localized in punctate structures that do not contain appreciable amounts of filamentous actin or the myosin tail-binding protein p127. This suggests that sqh mutant phenotypes are chiefly caused by sequestration of myosin into inactive aggregates. These results show that myosin II is responsible for a surprisingly diverse array of cell shape changes throughout development.

Regeneration in the medial-lateral axis of the insect thoracic segment

Development ◽  
1988 ◽  
Vol 102 (1) ◽  
pp. 175-192
Author(s):  
V. French ◽  
T.F. Rowlands
Keyword(s):  
Mirror Image ◽  
The Body ◽  
Dorsal Midline ◽  
Unequally Spaced ◽  
Polar Coordinate ◽  
Coordinate Model ◽  
Boundary Model ◽  
Almost All ◽  
Pattern Regulation ◽  
Lateral Axis

We have studied pattern regulation in the medial-lateral axis of the insect segment by grafting legs of beetle larvae (Tenebrio molitor) in different orientations into different positions medial and lateral to the leg site. The Boundary Model and Polar Coordinate Model of the insect appendage predict various patterns of supernumerary leg regeneration, and these grafts were designed to test the predictions. When a larval leg is grafted with normal anterior-posterior orientation medial to the normal leg, larvae and subsequent adults bear the graft plus a supernumerary leg. This is located where the lateral edge of the grafted leg confronted medial thorax (from the leg base across to the midline) and is orientated as a mirror image of the graft. The tarsal structure of supernumeraries resulting from grafts of the mesothoracic leg onto the metathorax shows that the supernumeraries may be derived from the graft, the host site or from both sources. Similarly, when a leg is grafted lateral to the leg site, a supernumerary forms at the confrontation between the medial edge of the graft and lateral thorax (from leg base across to the dorsal tergite). These results agree with the predictions of both models and would indicate that the compartments or the positional values extend out from the leg to the midline and the edge of the tergite. The two models differ in their predictions for the number, position and orientation of supernumeraries following 180 degree rotation of the grafted leg. When the rotated graft is placed lateral to the leg, larvae and adults form a single supernumerary which, in accordance with the Polar Coordinate Model, is lateral to the graft and orientated as a mirror image of it. However, the results of the corresponding medial graft cannot be readily explained by either model. Larvae form a single supernumerary either posterior or medial to the graft, suggesting a modified model with unequally spaced positional values, but the subsequent adult supernumeraries are almost all located medially. Experiments involving a graft placed medial to the leg site frequently show duplication of the adult midline suture, an extra branch forming between the thorax and the graft or supernumerary leg. In this case, as in the regeneration of the dorsal midline, the extreme medial structure is formed between two more lateral regions, which need not come from opposite sides of the body, but must have opposite mediolateral polarities. At present, no model can adequately explain all the results of grafting and extirpation on the insect ventral thorax.

scholarly journals Epithelial Morphogenesis Driven by Cell-Matrix vs. Cell-Cell Adhesion

2020 ◽  
Author(s):  
Shaohe Wang ◽  
Kazue Matsumoto ◽  
Kenneth M. Yamada
Keyword(s):  
Cell Adhesion ◽  
Single Cell ◽  
Cell Sheet ◽  
Branching Morphogenesis ◽  
Epithelial Morphogenesis ◽  
Epithelial Surface ◽  
Matrix Adhesion ◽  
Cell Matrix ◽  
Cell Matrix Adhesion ◽  
Cell Cell

SUMMARYMany embryonic organs undergo epithelial morphogenesis to form tree-like hierarchical structures. However, it remains unclear what drives the budding and branching of stratified epithelia, such as in embryonic salivary gland and pancreas. Here, we performed live-organ imaging of mouse embryonic salivary glands at single-cell resolution to reveal that budding morphogenesis is driven by expansion and folding of a distinct epithelial surface cell sheet characterized by strong cell-matrix adhesions and weak cell-cell adhesions. Profiling of single-cell transcriptomes of this epithelium revealed spatial patterns of transcription underlying these cell adhesion differences. We then synthetically reconstituted budding morphogenesis by experimentally suppressing E-cadherin expression and inducing basement membrane formation in 3D spheroid cultures of engineered cells, which required β1 integrin-mediated cell-matrix adhesion for successful budding. Thus, stratified epithelial budding, the key first step of branching morphogenesis, is driven by an overall combination of strong cell-matrix adhesion and weak cell-cell adhesion by peripheral epithelial cells.

Genes controlling cellular polarity in Drosophila

Development ◽  
1993 ◽  
Vol 119 (Supplement) ◽  
pp. 269-277 ◽  
Author(s):  
David Gubb
Keyword(s):  
Signal Transduction ◽  
Cell Membrane ◽  
Mirror Image ◽  
Fine Scale ◽  
Embryonic Cells ◽  
Cellular Polarity ◽  
Spatial Organisation ◽  
Large Numbers ◽  
Transmission Of Information ◽  
Segment Polarity

The control of cellular polarity is one of the least understood aspects of development. Genes have been identified in Drosophila that affect the polarity of embryonic cells in all three axes, apical-hasal, proximodistal and dorsoventral. Mutations that affect adult polarity are also known and mutant flies show several types of pattern alteration, including rotations and mirror-image duplications. Imaginal discs are much greater in size, however, than the embryo, and adult structures contain very large numbers of cells, many of which are not visibly differentiated with respect to their immediate neighbours. In regions where neighbouring cells are similar to each other, the imaginal polarity mutants alter the orientation of bristles and hairs but do not change cellular fate. Other regions, such as the tarsal segments of the legs, the ommatidia of the eye and the bracted bristle sockets on the tibia, behave as discrete fields. Within these fields, fine-scale mirror-image reversals and pattern duplications are observed, analogous to those caused by the embryonic segment polarity mutants. Thus, the polarised transmission of information can affect either orientation or fate depending on whether cells are differentiated from their immediate neighbours. Cellular polarity will be critically dependent on both the internal cytoskeletal architecture and the spatial organisation of signal transduction molecules within the cell membrane.

Arrest of intravitelline mitoses in Drosophila embryos by u.v. irradiation of the egg surface

Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 43-61
Author(s):  
Shin Togashi ◽  
Masukichi Okada
Keyword(s):  
Cell Cycle ◽  
Single Cell ◽  
Control Mechanism ◽  
Drosophila Embryo ◽  
Posterior Half ◽  
Simple Diffusion ◽  
Cytoplasmic Region ◽  
Anterior Half ◽  
Cytoskeletal Elements ◽  
Drosophila Embryos

The intravitelline mitosis in Drosophila was arrested at the anaphase within the span of a single cell cycle after irradiation with 300 nm u.v. Embryos at and before the 8-nucleus stage were influenced by the u.v. only when irradiated anteriorly, while at and after the 16-nucleus stage, embryos are sensitive to either anterior or posterior irradiation. In embryos anteriorly irradiated at or before the 8-nucleus stage all nuclei in the embryo were prevented from performing mitosis. When irradiated at or after the 16-nucleus stage, inhibition of the intravitelline mitosis is limited to the nuclei in approximately anterior-half region of embryos in anterior irradiation, and to those inapproximately posterior-half region in posterior irradiation, resulting in incomplete blastoderm formation. Sites sensitive to 300 nm u.v. are postulated to be present in the peripheral cytoplasmic region of the embryo and not in the nucleus, because the half-attenuation thickness of 300 nm u.v. light for the Drosophila egg cytoplasm is 3 µm and nuclei are at least 50 µm away from the periphery at the stage of irradiation. In addition lateral irradiation of a portion of an egg where there is no nucleus underneath was also effective in arresting division of nuclei in the same egg. It is suggested that the effects of 300nm u.v. may not be conveyed to the nuclei from the periphery by simple diffusion of a substance, and a hypothesis is proposed for the involvement of cytoskeletal elements associated with the u.v. sensitive sites on the surface to the control mechanism of the intravitelline mitosis of the Drosophila embryo.

Ouch! Single Cell Wound Repair in Drosophila Embryos

SciVee ◽  
2011 ◽  
Author(s):  
M.t. Abreu-blanco ◽  
J.m. Verboon ◽  
S.m. Parkhurst
Keyword(s):  
Single Cell ◽  
Wound Repair ◽  
Drosophila Embryos
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