"Kick-starting" male fertility

Adding a missing protein to infertile human sperm can 'kick-start' its ability to fertilise an egg and dramatically increase the chances of a successful pregnancy, a team of University scientists have uncovered. The team from the School of Medicine first found that sperm transfers a vital protein, known as PLC-zeta (PLCz), to the egg upon fertilisation. This sperm protein initiates a process called 'egg activation' which sets off all the biological processes necessary for development of an embryo. Now, the team has found that eggs that don't fertilise because of a defective PLCz, as in some forms of male infertility, can be treated with the active protein to produce egg activation. The added PLCz kick-starts the fertilisation process and significantly improves the chance of a successful pregnancy. "We know that some men are infertile because their sperm fail to activate eggs. Even though their sperm fuses with the egg, nothing happens.