Year in review: ‘Three-parent baby’ technique raises hope and concern
Safety and ethical questions surround controversial mitochondrial replacement therapy
![Embryo](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2016/12/4_122416_3parentbaby_main.jpg?fit=860%2C460&ssl=1)
SPINDLE SWAP A boy born in April has DNA from mom and dad, as well as mitochondria from a female donor. To make "three-parent" embryos, the chromosome-containing spindle, shown at the tip of the pipette, is removed from a woman's egg and inserted into a donor egg.
Center for Embryonic Cell and Gene Therapy/Oregon Health & Science Univ.