Cinematographical study of cell migration in the opened gastrula of Ambystoma mexicanum

Development ◽  
1978 ◽  
Vol 44 (1) ◽  
pp. 71-80
Author(s):  
H. Y. Kubota ◽  
A. J. Durston
Keyword(s):  
Cell Migration ◽  
Cell Body ◽  
Time Lapse ◽  
Ambystoma Mexicanum ◽  
Scanning Electron Micrographs ◽  
Neighbouring Cell ◽  
Posterior Process ◽  
Scanning Electron Micrography ◽  
Marginal Cells ◽  
Scanning Electron

The migration of inner marginal cells was studied in the Ambystoma gastrula, using scanning electron micrography and time-lapse cinemicrography. Scanning electron micrographs of gastrulae which were fixed while intact revealed that the migrating cells have flattened lamellipodia at their anterior end and a rounded cell body, which can sometimes be seen to be attached to a neighbouring cell by a slender posterior process. Films of opened gastrulae showed actively moving cells, with the same features described above. Details of their movements are reported and discussed in relation to the mechanism of gastrulation.

Conditioning of a culture substratum by the ectodermal layer promotes attachment and oriented locomotion by amphibian gastrula mesodermal cells

1983 ◽  
Vol 59 (1) ◽  
pp. 43-60 ◽  
Author(s):  
N. Nakatsuji ◽  
K.E. Johnson
Keyword(s):  
Cell Migration ◽  
Time Lapse ◽  
Ambystoma Maculatum ◽  
Specific Cell ◽  
Animal Pole ◽  
Micron Diameter ◽  
The Relationship ◽  
Extracellular Fibrils ◽  
Scanning Electron

We have found that ectodermal fragments of Ambystoma maculatum gastrulae deposit immense numbers of 0.1 micron diameter extracellular fibrils on plastic coverslips. When migrating mesodermal cells from A. maculatum gastrulae are seeded on such conditioned plastic substrata, they attach and begin migrating after 15–30 min in vitro. We did a detailed analysis of the relationship between fibril orientation and cell migration using time-lapse cinemicrography, scanning electron microscopy, and a microcomputer with a graphics tablet and morphometric program. We found that cells move in directions closely related to the orientation of fibrils. Usually fibrils are oriented in dense arrays with a predominance of fibrils running parallel to the blastopore-animal pole axis of the explant, and cells move preferentially along lines parallel to the blastopore-animal pole axis. When fibrils are unaligned, cells move at random. We have also shown that cells move with a slightly stronger tendency towards the animal pole direction. These results are discussed concerning the mechanism of specific cell migration during amphibian gastrulation.

scholarly journals Actin-dependent Lamellipodia Formation and Microtubule-dependent Tail Retraction Control-directed Cell Migration

2000 ◽  
Vol 11 (9) ◽  
pp. 2999-3012 ◽  
Author(s):  
Christoph Ballestrem ◽  
Bernhard Wehrle-Haller ◽  
Boris Hinz ◽  
Beat A. Imhof
Keyword(s):  
Cell Migration ◽  
Cell Body ◽  
Actin Polymerization ◽  
Green Fluorescence Protein ◽  
Time Lapse ◽  
Dependent Manner ◽  
Directed Cell Migration ◽  
Cell Front ◽  
Fluorescence Protein

Migrating cells are polarized with a protrusive lamella at the cell front followed by the main cell body and a retractable tail at the rear of the cell. The lamella terminates in ruffling lamellipodia that face the direction of migration. Although the role of actin in the formation of lamellipodia is well established, it remains unclear to what degree microtubules contribute to this process. Herein, we have studied the contribution of microtubules to cell motility by time-lapse video microscopy on green flourescence protein-actin- and tubulin-green fluorescence protein–transfected melanoma cells. Treatment of cells with either the microtubule-disrupting agent nocodazole or with the stabilizing agent taxol showed decreased ruffling and lamellipodium formation. However, this was not due to an intrinsic inability to form ruffles and lamellipodia because both were restored by stimulation of cells with phorbol 12-myristate 13-acetate in a Rac-dependent manner, and by stem cell factor in melanoblasts expressing the receptor tyrosine kinase c-kit. Although ruffling and lamellipodia were formed without microtubules, the microtubular network was needed for advancement of the cell body and the subsequent retraction of the tail. In conclusion, we demonstrate that the formation of lamellipodia can occur via actin polymerization independently of microtubules, but that microtubules are required for cell migration, tail retraction, and modulation of cell adhesion.

Regional differences in the morphology and motility of mesodermal cells from the early wing-bud of normal and talpid3 mutant chick embryos

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 185-203
Author(s):  
D. A. Bell ◽  
D. A. Ede
Keyword(s):  
Regional Differences ◽  
Time Lapse ◽  
Distal Region ◽  
Limb Bud ◽  
Scanning Electron Micrographs ◽  
Normal Cells ◽  
Wing Bud ◽  
Scanning Electron

A method of culturing has been employed to compare the properties of cells migrating from small mesodermal explants taken from different regions of normal and mutant limb-buds at different stages of development. An analysis by time-lapse cinematography of the morphology and mobility of cells migrating from explants defines a distal region within the limb-bud where these properties are distinct from those of cells from more proximal regions. In the normal wing-bud distal cells subjacent to the apical ectodermal ridge possess a characteristic multipolar morphology and translocate slowly in vitro. Cells from more proximal regions tend to be bipolar and translocate more rapidly. Distal and proximal cells also probably differ in their adhesive strengths. In the mutant, talpid3, distal and proximal cells do not differ in the above properties and cells from all regions of the limb-bud are multipolar, translocate slowly and are more adhesive than normal cells. A study of light micrographs and scanning electron micrographs suggests that these regional differences are found in the limb-bud in vivo and are not merely an effect produced by the in vitro culturing system.

Ectodermal fragments from normal frog gastrulae condition substrata to support normal and hybrid mesodermal cell migration in vitro

1984 ◽  
Vol 68 (1) ◽  
pp. 49-67
Author(s):  
N. Nakatsuji ◽  
K.E. Johnson
Keyword(s):  
Cell Migration ◽  
Cell Attachment ◽  
Cell Movement ◽  
Time Lapse ◽  
Mesodermal Cell ◽  
Inner Surface ◽  
New Evidence ◽  
Extracellular Fibrils ◽  
Scanning Electron

Using time-lapse cinemicrography and scanning electron microscopy, we have shown that normal Rana embryos and gastrulating hybrid embryos have extracellular fibrils on the inner surface of the ectodermal layer. These fibrils are absent prior to gastrulation and appear in increasing numbers during gastrulation. They can also be deposited in vitro where they condition substrata in such a way that normal presumptive mesodermal cells placed on them show extensive attachment and unoriented cell movement. These fibrils are also present in some arrested hybrid embryos, but in reduced numbers, or are lacking in other arrested hybrid embryos. Explanted ectodermal fragments from arrested hybrid embryos fail both to condition culture substrata by the deposition of fibrils and to promote cell attachment and translocation. In contrast, ectodermal fragments from normal embryos can condition culture substrata so as to promote moderate cell attachment and, for one particular gamete combination, even cell translocation of presumptive mesodermal cells taken from arrested hybrid embryos. These results provide new evidence to support the hypothesis that extracellular fibrils represent a system that promotes mesodermal cell migration in amphibian embryos. Differences in the fibrillar system in urodele and anuran embryos are discussed in relation to fundamental differences in the mode of mesodermal cell migration in these two classes of Amphibia.

Antiproliferative Effects of Pterodon pubescens Extract and Isolated Diterpenes in HaCaT Cells

Planta Medica ◽  
2020 ◽  
Author(s):  
Rosanna Tarkany Basting ◽  
Ilza Maria de Oliveira Sousa ◽  
Veronika Butterweck ◽  
Mary Ann Foglio
Keyword(s):  
Cell Migration ◽  
Methyl Ester ◽  
Local Treatment ◽  
Time Lapse ◽  
Molecular Structures ◽  
Brdu Incorporation ◽  
Hacat Cells ◽  
Antiproliferative Effects ◽  
Anti Inflammatory ◽  
Incorporation Assay

Abstract Pterodon pubescens fruits are popularly used because of their analgesic and anti-inflammatory actions, which are attributed to the isolated compounds with a vouacapan skeleton. This work aimed to evaluate the antiproliferative and anti-inflammatory effects of a P. pubescens fruit dichloromethane extract and the vouacapan diterpene furan isomerʼs mixture (1 : 1) (6α-hydroxy-7β-acetoxy-vouacapan-17β-oate methyl ester and 6α-acetoxy-7β-hydroxy-vouacapan-17β-oate methyl ester isomers) in HaCaT cells using the cell migration and the BrDU incorporation assay. Levels of IL-8 were measured by ELISA after TNF-α stimulation. HPLC/DAD analysis of the extract revealed the expressive presence of vouacapan diterpene furan isomerʼs mixture. P. pubescens extract (1.5625 – 25 µg/mL) and vouacapan diterpene furan isomerʼs mixture (3.125 – 50 µM) inhibited cell proliferation as indicated by a decreased BrdU-incorporation. For the evaluation of cell migration, time-lapse microscopy was used. P. pubescens presented inhibition on cell migration at all concentrations tested (3.125 – 12.5 µg/mL), whereas for the VDFI mixture, the inhibition was only observed at the highest concentrations (12.5 and 25 µM) tested. Furthermore P. pubescens extract and vouacapan diterpene furan isomerʼs mixture significantly decreased IL-8 levels. Our results showed antiproliferative and anti-inflammatory effects on HaCaT cells treated with the extract and the vouacapan isomerʼs mixture, without affecting cell viability. These activities could be attributed to the voucapan molecular structures. In conclusion, topical products developed of P. pubescens extract or the voucapan isomerʼs mixture should be further studied as a potential product for local treatment against hyperproliferative lesions as in psoriasis vulgaris, representing an alternative treatment approach.

A new genus and four new species of millipedes from Tasmania, Australia (Diplopoda: Polydesmida: Dalodesmidae), with notes on male leg setae in some Tasmanian dalodesmids

Zootaxa ◽  
2004 ◽  
Vol 558 (1) ◽  
pp. 1 ◽  
Author(s):  
ROBERT MESIBOV
Keyword(s):  
New Species ◽  
Electron Micrographs ◽  
Type Species ◽  
New Genus ◽  
Scanning Electron Micrographs ◽  
Scanning Electron

Bromodesmus catrionae n. gen., n. sp. (type species), B. militaris n. sp., B. riparius n. sp. and B. rufus n. sp. are described. The new genus is characterized by greatly reduced paranota and a gonopod telopodite expanded at the distal end into a posteriorly concave hood fringed with teeth; the hood partly protects a long, curved, acutely pointed solenomerite. Male leg setation in the type species of six Tasmanian dalodesmid genera is briefly discussed and illustrated with scanning electron micrographs. The sphaerotrichome shaft is sharply pointed in Atrophotergum; gently tapered in Dasystigma, Lissodesmus and Tasmanodesmus; expanded at the tip in Bromodesmus; and entirely absent in Gasterogramma. Tips of the setae forming the dense ventral brush on male podomeres are gently tapered in Dasystigma and Lissodesmus, truncated in Gasterogramma, expanded in Bromodesmus and forked in Tasmanodesmus.

The ultrastructure of the epidermis of the redia and cercaria of Parorchis acanthus, Nicoll. A study by scanning and transmission electron-microscopy

Parasitology ◽  
1971 ◽  
Vol 62 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Gwendolen Rees
Keyword(s):  
Electron Micrographs ◽  
Technical Assistance ◽  
Ventral Surface ◽  
The Body ◽  
Muscle Fibres ◽  
Scanning Electron Micrographs ◽  
Large Area ◽  
Transmission Electron ◽  
Parorchis Acanthus ◽  
Scanning Electron

Scanning electron-micrographs have shown the covering of microvilli on the surface of the redia of Parorchis acanthus. In the contracted state the elongated microvilli with bulbous extremities seen in the surface grooves may be the result of compression. The surface of the epidermis of the cercaria is smooth on a large area of the ventral surface and lattice-like with microvilli, laterally, anteriorly, dorsally and on the tail. The spines on the body can be withdrawn into sheaths by the contraction of muscle fibres inserted into the basement lamina below each spine.I would like to express my sincere gratitude to Dr I. ap Gwynn of this department for preparing the scanning electron-micrographs and the School of Engineering Science, University of North Wales, Bangor for the use of their stereoscan. I should also like to thank Mr M. C. Bibby for technical assistance and Professor E. G. Gray and Dr W. Sinclair for assistance with the transmission electron-micrographs.

scholarly journals Transformation and motility of human platelets: details of the shape change and release reaction observed by optical and electron microscopy.

1979 ◽  
Vol 83 (1) ◽  
pp. 126-142 ◽  
Author(s):  
R D Allen ◽  
L R Zacharski ◽  
S T Widirstky ◽  
R Rosenstein ◽  
L M Zaitlin ◽  
...  
Keyword(s):  
Shape Change ◽  
Human Subjects ◽  
Blood Platelets ◽  
Time Lapse ◽  
Human Platelets ◽  
Transformation Process ◽  
Epifluorescence Microscopy ◽  
Scanning Electron Micrographs ◽  
Dense Bodies ◽  
Short Wavelength Light

Blood platelets from 10 normal human subjects have been examined with a sensitive differential interference contrast (DIC) microscope. The entire transformation process during adhesion to glass is clearly visible and has been recorded cinematographically, including the disk to sphere change of shape, the formation of sessile protuberances, the extension and retraction of pseudopodia, and the spreading, ruffling, and occasional regression of the hyalomere. The exocytosis of intact dense bodies can be observed either by DIC microscopy, or by epifluorescence microscopy in platelets stained with mepacrine. Details of fluorescent flashes indicate that the dense bodies usually release their contents extracellularly, may do so intracytoplasmically under the influence of strong, short wavelength light on some preparations of mepacrine-stained platelets. The release of one or more dense bodies leaves a crater of variable size on the upper surface of the granulomere. Such craters represent the surface component of the open canalicular system and their formation and disappearance can be directly observed. Because these techniques permit quantitation of several parameters of motility which are not readily observable by other techniques, it is suggested that high extinction DIC microscope examination may become a rapid and useful method of studying congenital and acquired platelet disorders. Many features of platelet transformation have been confirmed and extended by scanning electron micrographs. These can in turn be interpreted by reference to time-lapse films of living platelets.

Aphid parasitoids infesting cotton, citrus, tobacco, and cereal crops in southeastern Europe: aphid-plant associations and keys

2005 ◽  
Vol 137 (5) ◽  
pp. 516-531 ◽  
Author(s):  
Nickolas G. Kavallieratos ◽  
Željko Tomanović ◽  
Christos G. Athanassiou ◽  
Petr Starý ◽  
Vladimir Žikić ◽  
...  
Keyword(s):  
Electron Micrographs ◽  
Separate Group ◽  
Cereal Crops ◽  
Scanning Electron Micrographs ◽  
Southeastern Europe ◽  
Line Drawings ◽  
Plant Associations ◽  
New Information ◽  
Aphid Parasitoids ◽  
Scanning Electron

AbstractWe present new information on the parasitoids (Hymenoptera: Braconidae: Aphidiinae) of aphids infesting cotton, tobacco, citrus, and cereal agroecosystems in southeastern Europe. Nineteen species are keyed and illustrated with scanning electron micrographs and line drawings. The aphidiines presented in this work have been identified from 18 aphid taxa. Furthermore, 96 original parasitoid–aphid–plant associations are presented. Cotton, tobacco, and citrus agroecosystems are connected through aphids and their parasitoids, whereas cereal agroecosystems represent a separate group of associations.

Use of electron microscopy to characterize the surfaces of flocculent and nonflocculent yeast cells

1989 ◽  
Vol 35 (12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Byron F. Johnson ◽  
L. C. Sowden ◽  
Teena Walker ◽  
Bong Y. Yoo ◽  
Gode B. Calleja
Keyword(s):  
Electron Microscopy ◽  
Fission Yeast ◽  
Budding Yeast ◽  
The Other ◽  
Yeast Cells ◽  
Scanning Electron Micrographs ◽  
Soft Or ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron

The surfaces of flocculent and nonflocculent yeast cells have been examined by electron microscopy. Nonextractive preparative procedures for scanning electron microscopy allow comparison in which sharp or softened images of surface details (scars, etc.) are the criteria for relative abundance of flocculum material. Asexually flocculent budding-yeast cells cannot be distinguished from nonflocculent budding-yeast cells in scanning electron micrographs because the scar details of both are well resolved, being hard and sharp. On the other hand, flocculent fission-yeast cells are readily distinguished from nonflocculent cells because fission scars are mostly soft or obscured on flocculent cells, but sharp on nonflocculent cells. Sexually and asexually flocculent fission-yeast cells cannot be distinguished from one another as both are heavily clad in "mucilaginous" or "hairy" coverings. Examination of lightly extracted and heavily extracted flocculent fission-yeast cells by transmission electron microscopy provides micrographs consistent with the scanning electron micrographs.Key words: flocculation, budding yeast, fission yeast, scanning, transmission.

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