Localization of autologous and heterologous serum antigens in the mouse ovary

Abstract

The ovarian localization of systemically injected bovine plasma albumin, rabbit globulin, and autologous serum antigens was examined in the mouse by the fluorescent antibody technique. Bovine plasma albumin injected intravenously was localized primarily in the follicular fluid, granulosa cell cytoplasm, zona pellucida, and oocyte in tertiary follicles and in the ovarian connective tissues. It was not detected in primary and secondary follicles nor in corpora lutea. Rabbit globulin was not detected in the ovary except when injected intraperitoneally at relatively high concentrations; localization in such instance was in low amount in the follicular fluid and granulosa cell cytoplasm of tertiary follicles. Antigenic molecules similar to or identical with mouse serum macromolecules were detected in the cytoplasm of most ovarian cell types including the oocytes of primary, secondary, and tertiary follicles. In addition, the autologous serum molecules were present in the follicular fluid and zona pellucida of tertiary follicles; they were not detected in ovarian connective tissues. These data demonstrate that antigens may be transferred from maternal serum to the oocyte in the mouse; they suggest strongly that macromolecular transfer occurs. It is hypothesized that similar serum-to-oocyte transfer of large molecules synthesized by the maternal organism is a necessary concomitant of normal mammalian oogenesis.