The uptake of [3H] glucosamine-labelled glycoconjugates into the perivitelline space of preimplantation mouse embryos.

Autoradiography has been used to follow the synthesis and migration of labelled glycoconjugates into fertilized and unfertilized mouse eggs. Adult female mice were paired individually with males and injected with 100 microCi [3H] glucosamine, either when they were paired with males or at the time a vaginal plug was first detected. The mice were killed at intervals after the injection of label and 5-microns and semi-thin sections of the oviducts were processed for autoradiography. Labelled glycoconjugates passed rapidly into the perivitelline space of fertilized and unfertilized mouse eggs. There was a positive correlation between the density of label within the zona pellucida and the perivitelline space. Labelled glycoconjugates were maintained within the perivitelline space of many developing embryos for at least 48 h despite very low levels of label within the oviduct by this time. Other 2-cell embryos were only lightly labelled. It is suggested that labelled glycoconjugates may be derived from secretions of the cumulus cells which surround the egg at ovulation rather than from oviductal secretions. [ABSTRACT FROM AUTHOR]