Nonhuman primate in vitro fertilization: biochemical changes associated with embryonic development

Little research has focused on the biochemistry of primate embryos fertilized in vitro. These studies were designed to examine alterations in cellular incorporation of leucine, uptake of steroid hormones, and overall viability of such embryos. The results may be applied to certain investigations of embryonic development in humans. Squirrel monkey ova and embryos were incubated in medium supplemented with either 3H-leucine, 3H-17 beta-estradiol (E2), or 3H-progesterone (P) and processed for autoradiographic analysis or assayed for radioactivity. Cellular incorporation of 3H-leucine (as an indication of protein synthesis), declined with oocyte maturation in vitro and remained constant at in vitro fertilization (IVF). The use of the vital dyes trypan blue and fluorescein diacetate showed high correlations with the cellular incorporation of 3H-leucine by ova, therefore demonstrating viability. Uptake of E2 and P increased at IVF. The results indicate normal metabolic development of primate embryos fertilized in vitro that is comparable to preimplantation development of other mammalian species.