DEVELOPMENTAL CAPACITY OF MOUSE OOCYTES THAT GROW AND MATURE IN CULTURE - THE EFFECT OF MODIFICATION OF THE PROTOCOL

Recent progress in the technology for growth and maturation of mouse oocytes in culture is described. The beneficial effect of modified systems for oocyte maturation and for preimplantation development on the developmental capacity of oocytes matured in vitro is demonstrated. The two most important changes in the culture systems are the use of Waymouth medium MB752/1 for oocyte maturation and CZB medium for preimplantation development. The overall result of using the new protocols is that the percentage of oocytes from unprimed and gonadotropin-primed immature mice that develop to blastocysts is approximately doubled. A system for the growth and development of oocytes isolated from preantral follicles that results in oocytes which have a full capacity for maturation, fertilization, and development to live young was developed. Use of Waymouth medium increases oocyte size during growth in vitro compared to other media tested. Continued improvements in the culture systems for oocyte and embryo development in vitro should provide excellent experimental systems for basic studies on the regulation of oocyte and embryo development as well as functional systems having practical applications. © 1990.