Assessment of nuclear transfer techniques to prevent the transmission of heritable mitochondrial disorders without compromising embryonic development competence in mice

Abstract

To evaluate and compare mitochondrial DNA (mtDNA) carry-over and embryonic development potential between different nuclear transfer techniques we performed germinal vesicle nuclear transfer (GV NT), metaphase-II spindle–chromosome-complex (MII-SCC) transfer and pronuclear transfer (PNT) in mice. No detectable mtDNA carry-over was seen in most of the reconstructed oocytes and embryos. No significant differences were seen in mtDNA carry-over rate between GV NT (n=20), MII-SCC transfer (0.29±0.63; n=21) and PNT (0.29±0.75; n=25). Blastocyst formation was not compromised after either PNT (88%; n=18) or MII-SCC transfer (86%; n=27). Further analysis of blastomeres from cleaving embryos (n=8) demonstrated undetectable mtDNA carry-over in all but one blastomere. We show that NT in the germ line is potent to prevent transmission of heritable mtDNA disorders with the applicability for patients attempting reproduction.