Culture of preantral ovarian follicles in the grey, short-tailed opossum, Monodelphis domestica.

A culture system designed to support the development of individual preantral mouse ovarian follicles has been employed to study follicle growth in the New World marsupial species Monodelphis domestica. Preantral follicles were isolated mechanically and cultured individually in microdrops under oil. Preliminary results indicate that follicle growth was positively correlated to the concentration of follicle-stimulating hormone (FSH) provided, with 1.0-1.5 IU FSH mL-1 producing the best results. Incubation at the body temperature of M. domestica (33 degrees C) was found to be preferable to that at 37 degrees C. The culture system was able to support follicle growth; however, despite follicles exceeding the size when antrum formation occurs in vivo, they remained preantral.