Modification of the nucleolar structure of the rat oocyte observed just before maturation.

ABSTRACT

Oocytes removed from antral follicles of 28- to 30-day-old rats treated with FSH (Folligon) show cavities and vesicles in the nucleoli. Repeated injections of Folligon significantly increase the frequency of these nucleolar inclusions. A possible relationship between intranucleolar cavities and rRNA metabolism has been suggested to account for this occurrence.