Effects of fatty acid supplementation during vitrification and warming on the developmental competence of mouse, bovine and human oocytes and embryos.

RESEARCH QUESTION

Does fatty acid supplementation in vitrification and warming media influence developmental competence in oocytes after vitrification and warming?

DESIGN

Mouse oocytes and four-cell embryos were vitrified and warmed with solutions supplemented with fatty acid and cultured to the blastocyst stage. To study lipid metabolism after vitrification, quantitative real-time polymerase chain reaction was used to analyse the expression of genes related to beta oxidation in mouse embryos vitrified and warmed with or without fatty acids. The effects of fatty acid supplementation in the warming solutions on the developmental competence of bovine and human embryos were analysed. Blastocyst outgrowth assay was used to evaluate the potential of human blastocysts for adhesion to fibronectin.

RESULTS

The neutral lipid content of mouse oocytes in the fatty acid 1% supplementation group was significantly higher than in the fatty acid 0% group (P = 0.0032). The developmental rate to the blastocyst stage was significantly higher in the fatty acid 1% group than in the fatty acid 0% group in mice (P = 0.0345). Fatty acid supplementation in warming solution upregulated Acaa2 and Hadha in mouse embryos. Fatty acids significantly improved the developmental ability of bovine embryos to the blastocyst stage (P = 0.0048). Warming with 1% fatty acid supplementation significantly increased the proportion of human blastocysts with morphological grade A inner cell mass (P = 0.0074) and trophectoderm (P = 0.0323).

CONCLUSIONS

Fatty acid supplementation in the warming solutions improved the developmental competence of vitrified-warmed mouse oocytes by activating the beta-oxidation pathway. Fatty acid supplementation enhanced the developmental rate of bovine embryos to the blastocyst stage and improved morphological characteristics of human embryos vitrified at the cleavage stage.