In-vitro enhancement of mouse embryonic development by co-culture with peritoneal macrophages.

The effects of peritoneal macrophages on mouse fertilization and embryonic development in vitro were examined by a co-culture method. In experiment 1, oocytes from F1 strain mice were inseminated and cultured with a monolayer of peritoneal macrophages to determine the effects of the macrophages on fertilization. In experiment 2, 1-cell embryos, fertilized in vivo from either a non-blocking or a blocking strain, were also incubated with peritoneal macrophages to determine whether these cells overcame the developmental arrest. Although the peritoneal macrophages had an adverse effect on fertilization in the F1 strain, embryonic development was significantly improved by the co-culture. This beneficial effect on embryonic development was also observed in the embryos fertilized in vivo from the strain that exhibited a 2-cell block. These results suggest that peritoneal macrophages provide an effective co-culture system for the in-vitro development of mouse embryos.