Some animals are capable of parthenogenesis, a reproductive process in which females produce offspring without fertilization.

In sea urchin and salmon sperm, the pH value regulates whether they remain immotile or swim. • An enzyme as a pH sensor: A rising pH activates soluble adenylyl cyclase (sAC) in sea urchins and fish.

Researchers at the MRC Laboratory of Medical Sciences (LMS) and Imperial College London have shown for the first time that, before they can start developing into egg and sperm cells, the embryonic ...