A previous study conducted in 1990 identified a specific gene, known SRY, in the Y chromosome was responsible for the development of male tissues in most mammals.
Now researchers looking into what makes the SRY gene switch on have found that an enzyme called JMJD1A is responsible for the unpacking of strings of DNA that leads to crucial genes being activated.
"We've found what causes SRY to become active in the right cells at the right time to make a male embryo. If you understand how these conditions arise, it helps people understand how their sex development is going to unfold. It helps with counseling and medical management, if they require it", Professor Peter Koopman, who has been part of both the studies, said.