Nonhuman primate in vitro fertilization: seasonality, cumulus cells, cyclic nucleotides, ribonucleic acid, and viability assays.

Since establishing our squirrel monkey (Saimiri sciureus) in vitro fertilization (IVF) system in 1972, 1788 oocytes have been laparoscopically recovered from follicles with 669 matured and 332 fertilized. Oocyte maturation was higher (P less than 0.05) from March to June. Among the oocytes, 50% showed first polar body extrusion by 21 hours after recovery. Maturation was significantly higher (P less than 0.05) in oocytes with corona radiata cells, compared with denuded oocytes. Sperm motility studies indicated that 2.6 and 5.2 mM caffeine enhanced motility by 10% to 30% over controls for the first 5 hours. Addition of 1 and 10 microM dibutyryl cyclic adenosine 3':5'-monophosphate (dbcAMP) enhanced fertilization by 50.3% and 50.0%, respectively. Preliminary studies of 3H-urindine incorporation and uptake by unfertilized oocytes showed levels of 3.43 +/- 0.21 and 55.01 +/- 7.16 fmole/embryo/3 hours, respectively. Exclusion of the vital dye trypan blue by oocytes and embryos gave a high correlation with morphology and survival. Autoradiographic analysis indicated nuclear grain densities in oocytes cultured with 3H-uridine. The results of the studies indicated that oocyte maturation was dependent on season and corona radiata cells, and that addition of dbcAMP enhanced IVF. Trypan blue was found be a useful embryo viability test.