Glycine transport in mouse eggs and preimplantation embryos

Abstract
In precompaction embryos glycine was taken up by the glycine-specific gly-system, which is concentrative, weakly exchangeable and dependent on Na+. After compaction glycine uptake increased, apparently due to the expression of the A-transport system and its reactivity with glycine. Studies of the metabolic fate of C from glycine indicated conversion to serine and alanine. Glycine could provide C for intermediary energy metabolism, resulting in CO2, as well as for macromolecular synthesis.