Embryo Culture in Teratological Surveillance and Serum Proteins in Development. Comprehensive Fourteen Year Report, 1968-1982

摘要

A testing procedure is being developed which may reduce the incidence of birth defects. The procedure uses in vitro cultures of whole rat embryos. Early studies on the nutrition of embryos involved attempts to culture whole chick embryos on protein-free chemically defined media. Media containing proteins from whole egg were superior. No single protein would support growth and development, at least two proteins were required. One protein was a transferrin, the second protein could be either ovalbumin or lipovitellin. To determine the path taken by nutrient proteins from medium to embryo, radioactive ovalbumin was prepared. The results showed that intact ovalbumin was taken up by the extra-embryonic yolk-sac and degraded to constituent amino acids within this structure. This observation was difficult to reconcile with the observed responses of the embryo to nutrient proteins. Consideration was given to yolk-sac function. When isolated yolk-sacs were incubated in Ringer's salt solution, they synthesized and secreted a distinct group of proteins. Yolk-sacs cultured on media containing various protein constituents synthesized serum proteins in relative amounts that were distinct for each medium. This suggested that the embryo responses to various culture media were mediated by changes in the relative synthesis of serum proteins. (ERA citation 07:058223)