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F Tripier-Darcy

Publications and source records attributed to F Tripier-Darcy.

4 recordsLinked to original sources

Ultrastructural and biochemical study of frog virus 3 uptake by BHK-21 cells.

Ultrastructural studies of the uptake of enveloped and naked frog virus 3 (FV 3) particles by BHK-21 cells have shown that enveloped viruses are internalized by adsorptive endocytosis via coated pits. The enveloped particles then appear to move through endosomes and finally lysosomes. Naked viruses may also follow the same pathway but only rarely. Their more frequent mode of entry is by fusion between the virus shell and the cellular membranes, thus allowing the virus to shed its nucleoprotein content directly into the cytoplasm. This difference in the mechanism of penetration has been confirmed by the use of lysosomotropic agents: the inhibition of viral growth being far more drastic for enveloped FV 3 than for naked virus implies that a lysosomal step is required for the multiplication of enveloped viral particles.

Animals↗

Ultrasonic absorption evidence for structural fluctuations in frog virus 3 and its subparticles.

The structural fluctuations specific to self-assemblies of biological molecules have been investigated further with ultrasonic techniques by using frog virus 3 (FV3). We compared the ultrasonic properties of complete FV3 virions and of several subparticles that may be obtained from this DNA virus: (i) the central nucleoprotein core versus its component DNA and proteins in a dissociated state; (ii) the core versus the capsidless subparticle, consisting of the core surrounded by the lipid membrane; and (iii) the complete virus versus the capsidless subparticle. The ultrasonic absorption by the core particle was quite large compared with the absorption by other nucleoprotein assemblies, suggesting that the core contains some organized structure. Both the core and the complete virus absorbed ultrasound more than did the capsidless subparticle. The difference spectrum for the virion relative to the capsidless subparticle may represent a single relaxation and is analyzed, by using a recent model, in terms of volume fluctuations due to radial movements in the virion. These fluctuations are much smaller than can be detected in virus crystals with present-day x-ray techniques.

Animals↗

Induction of intranuclear microtubules in chick embryo fibroblasts by frog virus 3.

Intranuclear microtubules appear in chick embryo fibroblasts upon infection with Frog Virus 3 (FV 3). Both the diameter and the annular shape of the microtubule profiles, established from electron microscopic observations using a goniometer, suggest that they are identical to naturally occurring cytoplasmic microtubules. Furthermore, the use of vinblastine allowed demonstration of the tubulin composition of the intranuclear microtubules.

Animals↗