Discovery Sheds New Light on Male Infertility

Researchers at The Chinese University of Hong Kong have made another big step forward in the study of male fertility with the discovery that an epithelial ion channel, the defect of which has been previously shown to result in female infertility, was also present in sperm and affecting male fertility. The finding was published online in the recent issue of the Proceedings of National Academy of Sciences of the US.

Sperm are not able to fertilize the egg unless they go through capacitation, which is known to be stimulated by bicarbonate. The research team of Prof Chan Hsiao Chang, director of the Epithelial Cell Biology Research Centre, in collaboration with Zhejiang Academy of Medical Sciences, demonstrated that cystic fibrosis transmembrane conductance regulator (CFTR) is involved in transporting bicarbonate into sperm, and thus, is vital to sperm fertilizing capacity and male fertility.

The research team reported for the first time that CFTR is detected in both human and mouse sperm. CFTR inhibitor or antibody significantly reduces sperm capacitation and the associated HCO3--dependent events.

These results suggest that CFTR in sperm may be involved in the transport of HCO3- important for sperm capacitation and that CFTR mutations with impaired CFTR function may lead to reduced sperm fertilizing capacity and male infertility other than CBAVD.