Therapies to overcome infertility in men could result from the discovery by Australian scientists of the key role a specific protein plays in sperm production.
The discovery, published today in inst PLoS Genetics, is supported in the same journal by a second work, involving the same researchers and Scottish colleagues, that identifies genes essential for sperm development.
Dr Liza O’Donnell, from Prince Henry’s Institute of Medical Research in Victoria, says the two papers are important because they pinpoint the protein essential to male fertility, katanin.
Named after the Japanese word for sword, katanin plays a critical role in cell shape, division and mobility as it “chops” up microtubules, which are the scaffold of a cell.
O’Donnell says katanin is found in most cells in the body and is highly expressed in the brain, where it is believed to play a key role in neuron development.
O’Donnell and her colleagues including Professor Moira O’Bryan, of Monash University’s Department of Anatomy and Developmental Biology, created mice that have a mutation in the p80 protein in katanin that regulates its microtubule-severing activities.
Katanin p80 in cells directs the severing enzyme to the right part of the cell and affects how well it works. Within the testes, it controls the formation, function and dissolution of microtubule structures intimately involved in sperm head shaping and tail formation.
A mutation in this protein leads to defects that affect the ability of the sperm to “swim” up the female’s reproductive tract and fertilise the egg.