Increase in postimplantation development of cultured mouse embryos by amino acids and induction of fetal retardation and exencephaly by ammonium ions

Abstract

The effects of amino acids and ammonium on the postimplantation development of cultured preimplantation mouse zygotes were assessed. Development after transfer revealed that the mouse embryo undergoes a switch in nitrogen requirements during the preimplantation period. Although Eagle's nonessential amino acids and glutamine supported the highest implantation and fetal development rates per embryo transferred when zygotes were cultured for 48 h, by 93 h of culture the highest implantation rate was observed when all 20 amino acids were in the culture medium. Furthermore, fetal development per implantation at 69 and 93 h of culture was increased only in the presence of essential amino acids wit..