To investigate cell surface changes associated with the development of uterine receptivity for ovoimplantation, isolated rabbit uterine epithelial cells will be maintained in primary cell culture. The cells will be incubated with [32P] orthophosphate and [3H] glucosamine, and patterns of labelled proteins in purified plasma membranes will be examined by polyacrylamide gel electrophoresis. Monoclonal antibodies prepared against epithelial plasma membrances will be screened against primary cultures of receptive and nonreceptive epithelial cells to detect stage-specific surface antigens. A functional role for such antigens in cell adhesion will be tested by use of stagespecific antibodies to block the binding of 125I-trophoblast membranes to the surface of epithelial cells in culture, and to epithelial plasma membrane proteins separated by electrophoresis and transferred to nitrocellulose filters. Failure of implantation is a common cause of human infertility. The results will provide evidence for the molecular basis of trophoblast-uterine epithelial cell attachment at ovoimplantation in an animal model.
