Quantitative and qualitative changes of mitochondria in human preimplantation embryos

Purpose The oxygen consumption rates (OCRs) in mice and cattle have been reported to change during preimplantation embryogenesis. On the other hand, mitochondrial DNA(mtDNA) copy number has been shown to be unchanged in mice and changed in cattle and pigs. The interactions between mitochondrial functions and mtDNA copy numbers in human embryos during preimplantation development remain obscure.