Gene knockouts that affect male fertility: novel targets for contraception.

There is an urgent need for a better method of contraception that is accepted, effective, and available, due the population explosion and unintended pregnancy. Various targets are being investigated that can be used for contraception. The ideal target should be non-steroidal, intercourse-independent, non-surgical, reversible, and non-barrier with no side effects. The gene knockout technology is a powerful approach to identify such novel targets. We identified at least 93 genes whose deletion demonstrated an effect on fertility in male mice till 2004 (1). In the present article, we found 71 additional gene knockouts in the database since the last report which demonstrated an effect on male fertility. The majority of these knockouts also demonstrated an effect on non-reproductive organs concomitant with an anti-fertility effect or effect on other organs was not examined. The knockouts of only a few genes/proteins induced a specific effect on fertility without a serious side effect. These genes/proteins may provide novel targets for contraception/contraceptive vaccine development.