Ooplasm donation in humans: the need to investigate the transmission of mitochondrial DNA following cytoplasmic transfer.

The use of cytoplasmic transfer as an assisted reproductive technique has generated much attention. This arises as donor mitochondria are introduced into the cytoplasm of the recipient oocyte. The consequences are the possible transmission of two mitochondrial (mt)DNA populations to the offspring. This pattern of inheritance is in contrast to the strictly maternal manner in which mtDNA is transmitted following natural fertilization and ICSI. This paper discusses the advantages of using such a technique to enhance embryonic development from poor quality oocytes with respect to the low copy number of mtDNA found in some oocytes following superovulation protocols. However, it also cautions against using such a technique before a clearer understanding of the patterns of inheritance and transmission of mtDNA has been established and suggests that animal models be utilised to do so.