The results of these studies on the role of follicle wall in the maintenance of the GV stage in bovine oocytes is supported by recent published data. In the present study, the percentage of oocytes that were maintained at the GV stage was significantly greater when oocytes were cultured within intact antral follicles. The majority (96.8%) of the oocytes obtained after 24-h follicle culture were arrested in GV stage; in contrast, culture of oocytes in hemisections or attached to part of the follicle wall maintained 62.7% and 24.6% of oocytes at the GV stage, respectively. buy ortho tri-cyclen
The nuclear morphology of oocytes from each method was assessed microscopically. Oocytes derived from follicle wall or hemifollicle cultures showed a range of degrees of abnormal chromatin condensation, from partially to totally condensed, while maintaining an intact nuclear envelope. The same abnormalities were observed when intact antral follicles were cultured submerged in the culture medium. Oocyte viability assessed by trypan blue exclusion indicated that these oocytes were dying at early stages of maturation.