Scientists discovered that making a very small change to female mice's DNA caused them to develop male reproductive organs.

One extra letter of DNA. That was all it took to override an entire chromosome’s worth of instructions and turn a female ...

Typically, female mouse embryos with two X chromosomes develop ovaries because a gene called Sox9 is suppressed. In male ...

A single DNA letter, inserted into a stretch of the genome that doesn’t code for any protein, was enough to turn genetically ...

Image of mouse embryos at the 2-cell stage visualised by light microscopy. Two blastomeres (cells) can be seen inside the zona pellucida (a “shell-like” protective outer layer) of each embryo. Credit: ...