METRO
Scientists have accidentally created a mouse embryo with six legs and no genitals – revealing how changes to DNA can have major impacts on development.
The team, from the Gulbenkian Science Institute in Oeiras, Portugal, were investigating how a particular protein works during the middle stages of embryo growth.
Embryos begin as just a bundle of identical cells. As they develop, cells specialise and begin to form different body parts, generally starting at the head and moving back towards the tail – yes, even humans have tails in the early days, but it disappears around eight weeks.
Scientists already knew that, in most four-limbed mammals, both the external genitalia (the penis or clitoris) and the hind limbs develop from the same early structures.
