Embryology. IVF of mouse ova in a simplex optimized medium supplemented with amino acids

The addition of amino acids to a modified simplex optimized medium (mKSOM) did not increase the percentage of blastocysts that develop from CF1 mouse ova fertilized in vitro. In contrast, the percentage of blastocysts that began to hatch and the number of cells in these blastocysts, particularly in the inner cell mass, was increased. The added amino acids also supported the development of a more organized extracellular matrix in the same blastocysts. The results suggest that zygotes produced in amino acid-supplemented mKSOM have a greater developmental potential, perhaps developing at a faster rate, than zygotes produced in mKSOM. This enhanced developmental potential may be caused by the alleviation of osmotic stress on the ova and zygotes by the amino acids that are osmolytes. The fertilization of human ova in vitro may benefit from the inclusion of free amino acids in the fertilizing medium. The availability of a medium that can be used to support both IVF and preimplantation development in the mouse is likely to benefit the recovery of mouse strains from cryopreserved spermatozoa.