A novel system for the co-culture of epididymal epithelial cells and sperm from adult rats

Abstract

To study interactions that occur between the epididymal epithelial cells and sperm within the epididymis during sperm maturation, a specialized co-culture system capable of supporting the differentiated function of these cell types must be utilized. A multifaceted approach has been devised to isolate plaques of epithelial cells from the epididymis of adult rats which involves microdissection, two collagenase digestions, and extensive pipetting and washing. The plaques of cells are cultured on a customized extracellular matrix within a primary semipermeable support and form into highly contiguous, but not confluent, regions of polarized epididymal epithelial cells during the first 2 days of culture. On Day 3, immature sperm are recovered from the caput epididymidis and placed within a second semipermeable support resting above the epithelial cells. During 24 h of co-culture, both sperm and epithelial integrity are maintained. Moreover, certain functions requisite to epididymal sperm maturation occur such as protein secretion by the epithelial cells, the association of secreted protein with the sperm, and the acquisition of progressive motility by the sperm. A comprehensive and illustrative description of this novel co-culture methodology is provided.