Mouse Embryo. Image credit: Jaqueline Isoppo da Cunha

Mouse Embryo. Image credit: Jaqueline Isoppo da Cunha

Medaka embryo. Image credit: Juan Ramón Morales

Medaka embryo. Image credit: Juan Ramón Morales

E6 chick embryo. Image credit: Yoshiko Takahashi

E6 chick embryo. Image credit: Yoshiko Takahashi