Effect of removal of the ovarian bursa of the rat on infundibular retrieval and subsequent development of ovulated oocytes.

The ovarian bursa was peeled from around one ovary of each rat and the rats were killed 1, 2, 3, 4 and 5 weeks later. The proportion of rats that maintained a bursa-free ovary did not change over the 5-week period (80-89%). Ovulation from the peeled ovary occurred in all rats but oocytes (1-4) were found in the ipsilateral oviduct in only 18% of the rats. The presence of oocytes in the oviduct was normally associated with some degree of re-encapsulation of the ovary. In another experiment rats were mated within 1 week of removal of the bursa from around the ovary. Unilateral pregnancy resulted in 92% of the rats. In a third experiment fertilized oocytes from mated donor rats were transferred into the oviduct next to the peeled ovary in 15 mated recipients. Of 85 zygotes transferred, 51 survived to be viable fetuses on Day 20. A single fetus developing from an endogenous oocyte was found in the transfer uterine horn in only one rat. This preparation may be useful in studies which attempt to determine the viability of oocytes that have undergone various manipulations in vivo or in vitro.