Scientists are exploring ways to mimic the origins of human life without two fundamental components: sperm and egg. They are coaxing clusters of stem cells – programmable cells that can transform into ...

The curved shape of a zebrafish egg causes unequal cell divisions, creating larger cells near the animal pole and smaller cells at the margin—a size gradient that controls the timing of everything ...

Nearly half the embryos studied underwent developmental arrest because of genetic mishaps in early development—a revealing insight that suggests more IVF babies could come to term with changes in the ...