Medically reviewed by Matthew Wosnitzer, MDMedically reviewed by Matthew Wosnitzer, MD Genetics plays a significant role in ...

Scientists have created a 6-legged mouse embryo with an extra pair of hindlimbs at the expense of their external genitalia. But far from creating a monster, this rudimentary rodent provides important ...

A new study in Nature shows that when pregnant mice don’t have enough iron, their (usually male) fetuses with a Y sex chromosome sometimes develop ovaries instead of testes. In other words, ...