Distribution of surface coat material on nasal folds of mouse embryos as demonstrated by concanavalin A binding

1979 ◽  
Vol 193 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Dorothy Burk ◽  
T. W. Sadler ◽  
Jan Langman
Keyword(s):  
Concanavalin A ◽  
Mouse Embryos ◽  
Surface Coat ◽  
Coat Material

scholarly journals Localization of concanavalin A binding carbohydrate in Chlamydomonas flagella

1984 ◽  
Vol 68 (1) ◽  
pp. 211-226
Author(s):  
B.E. Millikin ◽  
R.L. Weiss
Keyword(s):  
Electron Microscopy ◽  
Concanavalin A ◽  
Fluorescein Isothiocyanate ◽  
Surface Coat ◽  
Subsurface Zone ◽  
Flagellar Membrane

Chlamydomonas flagella are shown to possess two zones of concanavalin A (ConA) binding carbohydrate. The first zone, distinguished by a requirement for a prolonged labelling period for visualization of fluorescein isothiocyanate (FITC)-ConA fluorescence, is localized in the flagellar coat. The second zone is characterized by a rapid FITC- and [125I]ConA labelling subsequent to disruption of the flagellar membrane, but is unaffected by reagents that act only on the flagellar surface coat. Electron microscopy and ferritin-ConA labelling indicate that this subsurface zone is localized between the flagellar membrane and axoneme in the space that we term the flagelloplasm. These results are used to suggest possible functions for ConA binding glycosyl residues in flagella.

The surface coat of infective larvae of Trichinella spiralis

Parasitology ◽  
1999 ◽  
Vol 118 (5) ◽  
pp. 509-522 ◽  
Author(s):  
J. MODHA ◽  
M. C. ROBERTS ◽  
W. M. ROBERTSON ◽  
G. SWEETMAN ◽  
K. A. POWELL ◽  
...  
Keyword(s):  
Trichinella Spiralis ◽  
Amorphous Material ◽  
Protein S ◽  
Datura Stramonium ◽  
Metabolic Energy ◽  
Surface Coat ◽  
Microscopical Examination ◽  
Infective Larvae ◽  
Coat Material ◽  
Pronase Treatment

The surface coat of the infective larvae of the parasitic nematode Trichinella spiralis was characterized with respect to its biophysical properties, morphology and composition. Labelling of larvae with the fluorescent surface probe PKH26 was lost after activation (by incubation in mammalian medium containing trypsin and bile), or following pronase treatment. Electron microscopical examination revealed that pronase treatment resulted in the loss of an amorphous surface layer only, further demonstrating the specificity of PKH26 for the larval surface coat. Surface coat shedding was inhibited by sodium azide and carbonyl cyanide, or by incubation of larvae at 4°C, suggesting the shedding process required metabolic energy. Pre-labelled, unactivated larvae demonstrated continuous slow surface coat shedding and could be re-labelled with PKH26, indicating that the shed coat is replaced in these parasites. However, pre-labelled larvae which were activated failed to re-label with the probe, suggesting that activation provides an irreversible trigger for surface changes. PKH26, therefore, is a useful marker for larval activation. Examination of the shed coat material by scanning electron microscopy revealed 2 types of morphologies; one comprising thin multilaminate sheets and the other of amorphous material with ridges producing a fingerprint-like motif. Western- and lectin-blotting of the shed coat material demonstrated 2 prominent entities; a 90 kDa glycoprotein, which bound Datura stramonium agglutinin and was resistant to N- and O-glycanase treatment and a 47–60 kDa set of protein(s). Analysis of the surface lipids by electrospray mass spectometry revealed the presence of lysophosphatidic acid (lysoPA, C14[ratio ]2) and an unidentifiable component of 339·4 Da. These two lipids constituted 36·9% and 36% by mass of surface coat lipids respectively. The presence of lysoPA was confirmed by thin layer chromatography, which also detected phosphatidic acid (PA). The polar lipids detected in solvent rinses of intact parasites by electrospray mass spectrometry were PI (C48[ratio ]4), PE (C40[ratio ]4 and C38[ratio ]4), PS (C40[ratio ]4), lysoPC (C20[ratio ]2 and C18[ratio ]2) and lysoPA (C14[ratio ]2). These observations are discussed with respect to the role of the surface coat and its shedding in the T. spiralis host–parasite relationship.

The role of the cell surface in the migration of primordial germ cells in early chick embryos: effects of concanavalin A

Development ◽  
1978 ◽  
Vol 46 (1) ◽  
pp. 5-20
Author(s):  
H. Lee ◽  
N. Karasanyi ◽  
R. G. Nagele
Keyword(s):  
Cell Surface ◽  
Germ Cells ◽  
Concanavalin A ◽  
Primordial Germ Cells ◽  
Sublethal Dose ◽  
Chick Embryos ◽  
Con A ◽  
And Migration ◽  
Coat Material

Effects of concanavalin A (Con A) on the morphology and migration of primordial germ cells (PGCs) in stage-6 to -12 chick embryos were investigated. Con A, at a sublethal dose (10µg/ml), inhibited migration of PGCs from the germinal crescent area to other parts of the embryo. Affected PGCs were more rounded without the usual cytoplasmic extensions, but the integrity of other structures was unaffected. Nearly identical results were obtained with another lectin, wheat germ agglutinin (10µg/ml). Histochemistry using Con A-horseradish peroxidase revealed that PGCs in control embryos had a thin, rather uniform layer of extracellular coat material (ECM). Con A appeared to alter the distribution of ECM on PGCs, i.e. some parts of the cell surface were devoid of any detectable ECM, while others had small, scattered patches of ECM. Con A effects were alleviated by α-methyl-d-mannoside. Overall results of the present study indicated that the observed inhibition of PGC migration in early chick embryos is a consequence of Con A-induced alterations of cell surface properties.

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