Pressure-sensitivity of endoplasmic reticulum membrane and nucleolus as revealed by electron microscopy.

Murine erythroleukemia cells submitted to high hydrostatic pressure (up to 110 MPa, 17 min. at room temperature) remain viable (Mentré et al., 1997) but present, at the ultrastructure level, perturbations which are documented in this work.

Differential transcriptional activity associated with chromatin configuration in fully grown mouse germinal vesicle oocytes.

It was previously shown that fully grown ovarian germinal vesicle (GV) oocytes of adult mice exhibit several nuclear configurations that differ essentially by the presence or absence of a ring of condensed chromatin around the nucleolus. These configurations have been termed, respectively, SN (surrounded nucleolus) and NSN (nonsurrounded nucleolus). Work from our and other laboratories has revealed ultrastructural and functional differences between these two configurations.

Immunological properties and tissue localization of two different collagen types in annelid and vestimentifera species.

Rabbit antisera against cuticle and interstitial collagens from shallow sea water and hydrothermal vent annelids (Arenicola marina, and the pompeii worm Alvinella pompejana) and the vestimentiferan tube worm Riftia pachyptila showed a clear distinction between the two types of collagens, a broad cross-reactivity among the worm collagens and no reactions with various mammalian collagens. The antibodies reacted with various epitopes found on both triple helical and unfolded collagens. The cuticle collagens were localized by immunofluorescence to the outer surface of the epidermis and in annelids additionally to the anterior part of the digestive tract.

In situ and in vitro assembly of cuticle collagens from marine worms.

The in situ assembly of cuticular collagens is compared in a deep sea hydrothermal vent worm, the vestimenferan Riftia pachyptila, and a shallow sea water annelid, Arenicola marina. The in vitro assembly of their extracted collagen is compared following different methods of fixation. We show that the cuticle organization of the shallow sea water species A.