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

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.

1984 ◽  
Vol 68 (1) ◽  
pp. 49-67
Author(s):  
N. Nakatsuji ◽  
K.E. Johnson

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.


1983 ◽  
Vol 59 (1) ◽  
pp. 61-70
Author(s):  
N. Nakatsuji ◽  
K.E. Johnson

Previous studies have shown the presence of a network of extracellular fibrils on the inner surface of the ectodermal layer of the Ambystoma maculatum gastrulae. The alignment of the network along the blastopore-animal pole axis has suggested that the network of fibrils guides the migrating mesodermal cells in gastrulae by contact guidance. We have also shown that these fibrils can be deposited on substrata by explanted embryonic fragments and that substrata conditioned in this manner support directed cell migration. In this study, we found that the appearance of the fibrils in the embryos coincides with the start of cell migration towards the animal pole. Gastrulae of three urodele species examined (A. maculatum, A. mexicanum and Cynops pyrrhogaster) have similar dense networks of fibrils. Xenopus laevis gastrulae also have similar fibrils but fewer fibrils compared to urodele embryos. Rana pipiens gastrulae have very few extracellular fibrils. The scarcity of the fibrils in anuran species may be related to the differences in arrangement of mesodermal cells during migration.


Development ◽  
1978 ◽  
Vol 44 (1) ◽  
pp. 71-80
Author(s):  
H. Y. Kubota ◽  
A. J. Durston

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.


1985 ◽  
Vol 101 (4) ◽  
pp. 1487-1491 ◽  
Author(s):  
H Katow ◽  
M Hayashi

We studied the effect of fibronectin (FN) on the behavior of primary mesenchyme cells isolated from sea urchin mesenchyme blastulae in vitro using a time-lapse technique. The migration of isolated primary mesenchyme cells reconstituted in seawater and horse serum is dependent on the presence or absence of exogenous FN in the culture media. The cells in FN, 4 and 40 micrograms/ml, show a high percentage of migration and migrate long distances, whereas a higher concentration of FN at 400 micrograms/ml tends to inhibit migration.


1998 ◽  
Vol 72 (2) ◽  
pp. 1235-1243 ◽  
Author(s):  
Christopher M. Sanderson ◽  
Michael Way ◽  
Geoffrey L. Smith

ABSTRACT Many viruses induce profound changes in cell metabolism and function. Here we show that vaccinia virus induces two distinct forms of cell movement. Virus-induced cell migration was demonstrated by an in vitro wound healing assay in which infected cells migrated independently into the wound area while uninfected cells remained relatively static. Time-lapse microscopy showed that the maximal rate of migration occurred between 9 and 12 h postinfection. Virus-induced cell migration was inhibited by preinactivation of viral particles with trioxsalen and UV light or by the addition of cycloheximide but not by addition of cytosine arabinoside or rifampin. The expression of early viral genes is therefore necessary and sufficient to induce cell migration. Following migration, infected cells developed projections up to 160 μm in length which had growth-cone-like structures and were frequently branched. Time-lapse video microscopy showed that these projections were formed by extension and condensation of lamellipodia from the cell body. Formation of extensions was dependent on late gene expression but not the production of intracellular enveloped (IEV) particles. The requirements for virus-induced cell migration and for the formation of extensions therefore differ from each other and are distinct from the polymerization of actin tails on IEV particles. These data show that poxviruses encode genes which control different aspects of cell motility and thus represent a useful model system to study and dissect cell movement.


2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Ziyu Liu ◽  
Weiguan Zhang ◽  
Stella W. Pang

Abstract In the present study, 3D biomimetic platforms were fabricated with guiding grating to mimic extracellular matrix topography, porous membrane to resemble the epithelial porous interface and trenches below to represent blood vessels as an in vitro tissue microenvironment. Fabrication technologies were developed to integrate the transparent biocompatible polydimethylsiloxane platforms with preciously controlled dimensions. Cell migration behaviors of an immortalized nasopharyngeal epithelial cell line (NP460) and a nasopharyngeal carcinoma cell line (NPC43) were studied on the 2D and 3D platforms. The NP460 and NPC43 cells traversing through the porous membrane and migrating in the trenches below were studied by time-lapse imaging. Before traversing through the pores, NP460 and NPC43 cells migrated around the pores but NPC43 cells had a lower migration speed with less lamellipodia spreading. After traversing to trenches below, NPC43 cells moved faster with an alternated elongated morphology (mesenchymal migration mode) and round morphology (amoeboid migration mode) compared with only mesenchymal migration mode for NP460 cells. The cell traversing probability through porous membrane on platforms with 30 μm wide trenches below was found to be the highest when the guiding grating was perpendicular to the trenches below and the lowest when the guiding grating was parallel to the trenches below. The present study shows important information on cell migration in complex 3D microenvironment with various dimensions and could provide insight for pathology and treatment of nasopharyngeal carcinoma.


Author(s):  
Virginia Fonte ◽  
Nancy Weller ◽  
Keith R. Porter

The surfaces of a cell in its topography and anti-genicity expresses subtle variations in the effective genome, as well as the physiology and structural organization of the underlying cytoplasm. Understanding the relationship of these various factors to the surface depends in part on obtaining a detailed characterization of the topography of cells and how this topography changes with phases in the cell cycle, with transformation to malignancy and with the cell's response to such physiologically active agents as cyclic AMP.We have therefore explored the usefulness of the scanning electron microscope in investigations of the cell's topography. Cells grown under favourable in vitro conditions have been fixed in glutaraldehyde, dehydrated in acetone and dried by the critical point method of Anderson.


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