A simple flow-through micro-chamber for handling fragile, small tissue explants and single non-adherent cells.

The flow-through chambers described are easily assembled in the laboratory with no need for sophisticated or expensive equipment. They allow for treating micro-explants or single non-adhesive cells with different solutes for defined times by easy and quick changes of the medium in the chambers. The specimen can be fixed, immunostained and observed microscopically within the chamber.

Cell surface proteins during early Xenopus development: analysis of cell surface proteins and total glycoproteins provides evidence for a maternal glycoprotein pool.

The populations of cell surface proteins and total glycoproteins were investigated in early Xenopus embryos through lectin staining, affinity binding of glycoproteins to lectins, and use of a succinimide ester to biotinylate cell surface molecules. Lectin staining shows that the egg is endowed with a thick layer of surface glycoprotein, and that glycoprotein is immediately detected on the newly formed membranes of nascent blastomeres. The amount of glycoprotein found in eggs and early embryos remains constant, and electrophoretic analysis reveals no changes in abundant lectin-binding glycoproteins through the neurula stage.

The fate of oocyte nuclear proteins during early development ofXenopus laevis.

The localization and movements of four nuclear proteins, originally contained in the germinal vesicle ofXenopus oocytes, were followed through early development from cleavage to late neurula. The study made use of monoclonal antibodies directed against germinal vesicle proteins. Biochemical methods showed that all proteins persist in the embryo without a change in molecular size or gross concentration.

Tissue specific nuclear antigens in the germinal vesicle ofXenopus laevis oocytes.

A library of hybridoma cell lines has been established which produce monoclonal antibodies against antigens from the germinal vesicle ofXenopus laevis oocytes. Many of the antigens are also found in the nuclei ofXenopus embryonic cells in culture. The fate of two of these antigens during embryogenesis was traced by immunofluorescence on embryo and tadpole sections.