Introduction:Asthenozoospermia,or low sperm motility,is a common cause of human male infertility.It has reported that about 20% of male infertility is caused by asthenozoospermia and 80% of male infertility is related to altered motility.In spite of the importance of sperm motility to male fertility,reduced sperm motility remains only a clinical sign of infertility,and people actually understand very little about the molecular mechanism of sperm motility.