Two proteins in a family of proteins known as PLA2s as crucial for sperm function and fertility in mice.
The studies from two independent groups may underlie infertility or help develop a male contraceptive.
Researchers led by Makoto Murakami, at The Tokyo Metropolitan Institute of Medical Science, Japan, found that sPLA2-III was expressed proximal epididymal epithelium region of thetestes.
Mice lacking this protein had substantially decreased fertility. Their sperm did not mature properly showed decreased motility and reduced ability to fertilize eggs in vitro.
In the second study, researchers led by Christophe Arnoult, at Grenoble Institute of Neuroscience, France, found in mice that group X secreted PLA2 (also known as mGX) was a predominant constituent of a compartment in sperm known as the acrosome.
Acrosome has a key role in breaking down the coat that surrounds the ovum so to make fertilization possible.
Male mice lacking mGX produced smaller litters and were not efficient at fertilizing eggs in vitro. The presence of molecules that inhibit either mGX or secreted PLA2s reduced the efficiency of invitro fertilization (IVF).
Additional mGX improved the efficiency of IVF.
This research may provide a caution to researchers developing drugs that target members of this closely related proteins to treat hardening of the arteries (atherosclerosis) and inflammation
