SUCCESSFUL RECOVERY OF PREIMPLANTATION EMBRYOS BY NONSURGICAL UTERINEFLUSHING IN THE BONNET MONKEY

A major limitation to progress in primate embryology is the lack of an adequate supply of preimplantation embryos. We describe a method for recovering preimplantation-embryos in bonnet monkeys (Macaca radiata) using a nonsurgical uterine flushing technique similar to the one prev iously employed in rhesus monkeys. Forty cyclic females were screened for cervical cannulation, and 10% of these had an impassable cervix. E leven females suitable for cannulation were selected,and 27 menstrual cycles were monitored over a 5-mo period. Seventy-one percent of the c ycles showed estrogen peaks, which were observed between Days 9 and 14 of the cycle. Following natural mating, uterine flushings were perfor med on Days 5 to 8 of pregnancy (Day 0 = the day following the estroge n peak). Of the 27 recovery attempts, 9 (33.3%) resulted in the recove ry of ovulation products, including those of an unfertilized oocyte an d empty zona (2 cases), retarded cleavage-stage (4 to 8-cell) embryos (4 cases), morula (1 case) and balstocysts (2 cases). These results sh ow, for the first time, that the nonsurgical uterine flushing techniqu e can be successfully performed to recover uterine-stage preimplantati on embryos from bonnet monkeys. (C) 1997 by Elsevier Science Inc.