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IN VITRO/IN VIVO COMPARISON OF YOLK SAC FUNCTION AND EMBRYO DEVELOPMENT
Citation:
Andrews, J., M. McCoy, R. Zucker, K. Elstein, AND J. Rogers. IN VITRO/IN VIVO COMPARISON OF YOLK SAC FUNCTION AND EMBRYO DEVELOPMENT. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-92/066.
Description:
Yolk sac function and development of rat embryos grown in vitro for 24 hrs starting on day 10.5 were compared to those of embryos grown in utero. he embryos grown in vitro had significantly fewer somites, shorter crown-rump length and smaller yolk sac diameter when compared to the in vivo embryos but all values were within the normal range for this stage of gestation. ead length was not significantly different between the two groups. ucleated yolk sac red blood cell (RBC) cellular and nuclear volumes (Coulter counter) were not significantly different between the two groups. BC cell cycle analyses by flow cytometry did not reveal any difference between in vitro and in vivo embryos. Yolk sacs gamma-glutamyl transferase (GGT), sorbitol dehydrogenase (SDH), transferrin (TF), alpha-fetoprotein (AFP), protein, triglyceride, lactate dehydrogenase (LDH), alkaline phosphatase, cholesterol, urea nitrogen (BUN), and GOT concentrations were monitored in the two groups. he in vitro embryos had significantly lower GGT and SDH activities. FP is synthesized by the yolk sac at this stage of development and was significantly lower in the in vitro embryos. F is transported across the yolk sac to the embryo and was significantly higher in the in vitro embryos. hese data indicate that impaired yolk sac function may in part be responsible for the developmental delay and the short-term embryonic survivability seen in cultured embryos.