What is maternal spindle transfer?
The maternal spindle, named after its spindle shape, is a structure within the egg containing the mother’s nuclear DNA. Maternal spindle transfer (MST) involves transferring the spindle from the intended mother’s egg and placing it into a donor egg with healthy mitochondria (from which the donor's spindle, and therefore the nuclear DNA, has been removed). The mother's egg, now without any nuclear DNA, is destroyed.
This creates a healthy egg which can then be fertilised with the intended father’s sperm.
As with pro-nuclear transfer (PNT), the resulting embryo will contain nuclear DNA from the intended father and mother, and mitochondrial DNA from the egg donor.
This method is different from PNT as eggs rather than embryos are destroyed in the process.
Step by step: how maternal spindle transfer works
MST involves genetically modifying a human egg, which is not currently permitted in treatment in the UK. Explore the ethical issues associated with this medical technique: