Sperm storage and degradation in the ovary of a marine copulating sculpin, Alcichthys alcicornis (Teleostei: Scorpaeniformes): Role of intercellular junctions between inner ovarian epithelial cells.

The morphology of female sperm storage during the spawning period and the morphology of sperm degradation after the spawning period were investigated by electron microscopy in a copulating teleost, Alcichthys alcicornis. The spermatozoa were maintained in the ovarian cavity, floating in the ovarian fluid during the spawning period. The spermatozoa then degenerated and were phagocytized by macrophages invading the ovarian cavity after the spawning period. In the ovary during the spawning period, horseradish peroxidase used as a tracer revealed tight junctional complexes connecting adjacent cells of the inner ovarian epithelia (ovarian wall epithelium and ovigerous lamella epithelium). This indicates that a compartmentalization of the ovarian cavity occurs during the spawning period. The junctional complexes were breached after the spawning period, as shown by the fact that horseradish peroxidase penetrated the ovarian cavity via the intercellular space between the adjoining ovigerous lamella epithelia. These results suggest that the spermatozoa in the ovarian cavity are isolated from the maternal immune system by the tight junctional complexes between the adjoining inner ovarian epithelia during the spawning period, and then are eliminated by immune cells following the breakdown of the junctional complexes after the spawning period. J. Morphol. 233:153-163, 1997. © 1997 Wiley-Liss, Inc.