CELL-TO-CELL COMMUNICATION OF EQUINE UTERINE TUBE (OVIDUCT) CELLS AS DETERMINED BY ANCHORED CELL ANALYSIS IN CULTURE

Cell culture systems using uterine tube (oviduct) epithelial cells (UTEC) have been described in several species; however, the presence and relative degrees of cell coupling occurring between these cells is unknown. This study was done to evaluate the cell-to-cell communication of cultured equine UTEC obtained from mares in the follicular phase. Monolayers of cells were grown from either primary explants or from passaged and frozen-thawed UTEC. Cell-to-cell communication via gap junctions was measured by an anchored cell analysis and sorting computerized workstation. The UTEC were labeled with carboxyfluorescein diacetate. Specific cells located in cell aggregates were photo-bleached, then the percentage of fluorescence recovery through gap junction mediated dye diffusion from neighboring cells was determined. Levels of cell communication and changes in intracellular calcium were also measured for UTEC before and after the addition of stallion sperm cells to the cell aggregates. The UTEC of both primary and passaged frozen-thawed cells showed cell coupling in vitro, with almost all cells having some fluorescence recovery. There was no difference in the percentage of fluorescence recovery seen between primary or passaged frozen-thawed UTEC cell groups (P = 0.24). The addition of sperm cells to the monolayer cells increased intracellular UTEC calcium levels (P < 0.001). There was also a tendency (P = 0.07) for UTEC coupling to increase in sperm cell co-culture. However, UTEC contraction and movement of the monolayer cells after co-culture with sperm cells made it difficult to accurately follow individual cells with a fluorescence--based anchored cell analysis and sorting workstation. This study indicates that equine UTEC display gap junction mediated cell communication in culture.