The Effect of Cell-to-Cell Contact on the Surface Morphology of Chinese Hamster Ovary Cells

Rubin, Robert W.; Everhart, Leighton P.

doi:10.1083/jcb.57.3.837

Cited by 95 publications

(28 citation statements)

References 9 publications

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“…For example, CHO cells in confluency, observed during the cell cycle, go through a series of morphological changes which includes during S and G2 a relatively well-spread lamellar form (13) . The same cells maintained in a very sparse culture where little or no contact is achieved retain during most of the cycle a humped-up form more characteristic of GI (19) . Thus it appears that cell form is one expression of contact inhibition of growth and movement .…”

Section: Discussionmentioning

confidence: 99%

A Scanning Electron Microscope Study of Surface Features of Viral and Spontaneous Transformants of Mouse Balb/3t3 Cells

Porter

Todaro

Fonte

1973

The Journal of Cell Biology

161

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Cells of the mouse line Balb/3T3 as well as three virus-induced transformants and two spontaneous transformants grown in vitro have been studied for their topography by scanning electron microscopy . The parent cell in confluent culture closely resembles an endothelial cell in its form and in the structure of its association with adjacent cells . The tumorigenic transformants produced by SV40, murine sarcoma virus, or polyoma viruses are fusiform to pleomorphic and distinctly different from the cell of origin . They show relatively smooth surfaces except for blebs and marginal microvilli . Perhaps most surprising is the similarity they bear to one another. This is made the more singular by the very different form shown by the tumorigenic transformants of spontaneous origin . One of these, S2-4, possesses a thickened rather than the lamellar form of the parent A31 cell and is covered by long microvilli and many spherical blebs . The other, TuT3, more closely resembles the cell of origin but shows extensive ruffling at its margins . All transformants grow without evidence of contact inhibition .The significance of the surface morphologies and the factors influencing cell form are discussed .

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Section: Discussionmentioning

confidence: 99%

A Scanning Electron Microscope Study of Surface Features of Viral and Spontaneous Transformants of Mouse Balb/3t3 Cells

Porter

Todaro

Fonte

1973

The Journal of Cell Biology

161

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“…Scanning electronmicroscopy studies' indicate that RBL-1 cells have approximately the same number of folds and microvilli on cells derived from a stationary culture (more than 80% G, cells) and on cells derived from a culture in which more than 50% of the cells were in the S phase . Thus, unlike CHO cells, shown to have more peripheral processes in the G, phase and less in the S phase (35,36), RBL-1 cells seem to have the same surface morphology in S and G, phase and therefore a relatively constant, albeit nonlinear, relationship between volume and surface area . Consequently, our data suggest a higher density of receptors per unit area in the stationary cells .…”

Section: Discussionmentioning

confidence: 99%

Cell cycle-associated changes in receptors for IgE during growth and differentiation of a rat basophilic leukemia cell line.

Isersky¹,

Metzger²,

Buell³

1975

The Journal of Experimental Medicine

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The rat basophilic leukemia cells (RBL-1) have histamine-containing granules and receptors for IgE (1-3) . The normal analogues of these cells (basophils and/or mast cells) are difficult to obtain in sufficient number and/or purity for detailed study; hence the tumor cell line may be useful for a variety of investigations . For example, the RBL-1 cells are so far the only ones in which a rigorous analysis of the IgE-membrane receptor interaction has been possible . Similarly, the RBL-1 cells are the most promising available for the isolation and characterization of the receptor, as well as an analysis of its organization within the membrane . This receptor is likely an important participant in antigen-induced IgE-mediated histamine release, yet nothing is known about its structure .During the course of our studies, we observed that the IgE-binding capacity of cultured RBL-1 cells varied quite widely from culture to culture. The present study was undertaken to explore this phenomenon . We have found that the variations can be accounted for by changes in the number of receptors during the cell cycle and the distribution of cells in different phases of their cycle in cultures at various stages of growth . Materials and MethodsCell Culture. Rat leukemia basophils (RBL-1) were grown in spinner flasks in Eagle's minimum essential medium with Earle's salts (EMEM)' supplemented with 20% fetal calf serum (FCS) 0.06% glutamine, 100U/ml penicillin, and 100,ug/ml streptomycin . Three growth patterns were examined : (a) Cells from a stationary phase culture were resuspended in fresh medium and allowed to reach high density and remain in stationary phase for up to 72 h. (b) Cultures were maintained in exponential growth by daily dilutions with fresh medium at a ratio of 1:2 or 1:3 . (c) Synchronized cultures were derived from exponential cultures by using a double thymidine block procedure (below) . Cell viability was determined by 0.08% trypan blue exclusion. Cell counts and volume distribution curves were obtained with a Coulter Counter Model B standardized with mulberry pollen (12-14 pm in diameter) and equipped with a Coulter Channelizer and an x, y plotter (Coulter Electronics Inc., Hialeah, Fla.) . The volumes given in this report are either the weighted average (for mixed populations) or the

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“…When studying dividing cells it is sometimes difficult to differentiate mycoplasma from the blebs and other structures that appear on cell surfaces in anaphase and telophase (and possibly at other stages of the cell cycle) (20,23). Under these conditions, morphology alone may not be sufficient for the definitive identification of mycoplasma, and we therefore used the techniques described below to identify the organisms.…”

Section: Resultsmentioning

confidence: 99%

Interaction of Mycoplasmas with Cell Cultures, as Visualized by Electron Microscopy

Brown

Teplitz

Revel

1974

Proc. Natl. Acad. Sci. U.S.A.

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Mycoplasmas were examined on the surfaces of tissue culture cells prepared for transmission and scanning electron microscopy. The pleomorphic bodies seen were proved to be mycoplasmas by the use of thin sections, passage of the infection from one cell line to another, and by autoradiography with [3H]thymidine both on the sections and the replicas. The mycoplasmas were not always evenly distributed over the cell's surface; their arrangement seemed to correlate with the activity or morphology of the cell. The use of replicas and scanning electron microscopy in routine examination of cultures for mycoplasma contamination is discussed.A number of surveys (9,11,15,27) indicate that many cell cultures, particularly when grown in the presence of antibiotics (10,15), are contaminated with mycoplasmas, and undetected infections have been an important source of artifact in many experiments (27).There are established techniques for the detection and identification of mycoplasmas (3,9,14,15,27,29). Many, however, are time consuming and complex. We have now found that very simple electron microscopic techniques such as cell-surface replicas (8,21,22) can provide a rapid and sensitive assay for the presence of mycoplasmas in tissue cultures. If available, scanning electron microscopy (5) can also be used to good advantage. This paper describes the morphology of mycoplasmas as observed in replicas and in preparations for the scanning electron microscope (SEM), presents an electron microscope autoradiographic technique for identification of these organisms in replicas, and discusses preliminary data on the interactions of culture cells with mycoplasmas. MATERIALS AND METHODSWe have examined cells from a number of different types (BHK, 3T3, Cl-1-D, LA9, L929, LD, HeLa, ME180, Chimp, CV-1, and AGMK), often obtaining the same cell line from a number of different sources. These cells were cultured on glass coverslips in the absence of antibiotics. * They were fixed before reaching confluency in 2.5% glutaraldehyde-0.5% osmium tetroxide in 0.1 M cacodylate buffer pH 7.4 at 0C (12). After dehydration in a graded series of ethanols, they were dried from Freon in a critical-point bomb (6). If lower-quality replicas can be tolerated (see Discussion) one can also dry the Abbreviation: SEM, scanning electron microscope. * Mycoplasma contamination can be detected in the presence of antibiotics. However, we have found that cells may need to be grown without antibiotics for several weeks before the mycoplasmas are present in more than marginally detectable numbers.samples from amyl acetate (21). For examination in the scanning electron microscope (ETEC; ETEC Corp., Hayward, Ca.), coverslips were rotary coated with gold. For transmission electron microscopy, samples were shadowed at a 450 angle with platinum-palladium (80:20) and at a 900 angle with carbon; the replicas were floated off the glass with hydrofluoric acid; and the cells were digested away with Clorox (21). The replicas were then rinsed in water, picked up on grids, and e...

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The Effect of Cell-to-Cell Contact on the Surface Morphology of Chinese Hamster Ovary Cells

Cited by 95 publications

References 9 publications

A Scanning Electron Microscope Study of Surface Features of Viral and Spontaneous Transformants of Mouse Balb/3t3 Cells

A Scanning Electron Microscope Study of Surface Features of Viral and Spontaneous Transformants of Mouse Balb/3t3 Cells

Cell cycle-associated changes in receptors for IgE during growth and differentiation of a rat basophilic leukemia cell line.

Interaction of Mycoplasmas with Cell Cultures, as Visualized by Electron Microscopy

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