Effect of recombinant human gonadotrophins on human, bovine and murine oocyte meiosis, fertilization and embryonic development in vitro

The response of murine, bovine and human oocytes to pure recombinant prepar ations of human follicle stimulating hormone (rFSH) and luteinizing hormone (rLH) for meiotic maturation and subsequent developmental competence in vi tro were examined in the present experiments. Maturation of immature bovine oocytes to the metaphase II stage was significantly increased by the addit ion of 1 IU/ml of rFSH in combination with either 1 IU/ml rLH or 10 IU/ml r LH. Similarly, embryonic development to the blastocyst stage was improved i n bovine oocytes treated with a 1:10 combination of rFSH:rLH. However, no s ignificant difference was observed in the number of inner cell mass or trop hectoderm cells of the resulting blastocysts, Although the increased matura tion to metaphase II was not significant, human embryonic developmental com petence was improved by maturing oocytes in the presence of a 1:10 ratio of rFSH:rLH as only those oocytes exposed to a 1:10 ratio of rFSH:rLH during maturation showed normal cleavage patterns beyond day 2. In addition, 1 IU/ ml rFSH and 1 IU/ml rLH increased the expression of oocyte proteins in huma n oocytes. The inclusion of recombinant gonadotrophins, either singly or in combination, had no significant effect on the maturation, fertilization or embryonic development of in-vitro matured mouse oocytes. These data provid e support for the responsiveness of human and bovine oocytes to gonadotroph ins in vitro and the need to consider variations in the relative concentrat ions for optimization of oocyte developmental competence.