Nicotinamide mononucleotide supports the development of bovine embryo through enhancement of mitochondrial function in morula.

NAD+ is an important regulator of cellular physiological processes. However, in the culture environment, NAD+ levels are predicted to decrease below physiological requirements. Therefore, we examined the effects of the NAD+ precursor nicotinamide mononucleotide (NMN) on NAD+ levels and viability of mammalian fertilized ova. NAD+ levels decreased during in vitro culture, but this decrease was alleviated by NMN. NMN also increased the blastocyst formation rate and accelerated the developmental rate. Transcriptome analysis showed that NMN induced significant changes in the expression of genes involved in mitochondrial function in morula, and that NMN increased mitochondrial membrane potential, oxygen consumption rate and mitochondrial DNA copy number of morula while reducing reactive oxygen species levels. The addition of NMN to the embryo culture medium increased NAD+ levels in embryos, boosted mitochondrial function at the morula stage, and enhanced their ability to develop into blastocysts.