- They inserted a light-activated enzyme for cAMP synthesis into mouse sperm that lacked the endogenous enzyme. Sperm of these mice are usually non-motile, and the mice consequently infertile. After stimulation of these sperm with blue light, they produce cAMP, start to swim again, and are even able to fertilise eggs.
- Fertilisation of egg cells is closely linked with cAMP synthesis. Sperm lacking the endogenous adenylate cyclase enzyme are unable to swim: the mice are infertile. However, if the bPAC sperm are stimulated with blue light, the cAMP concentration increases and the sperm swim faster, because the sperm tail beats faster.
- This proves that it is possible to control something as fundamental as fertilisation with light. Optogenetics has thus conquered another field outside the neurosciences.