Sarah George - Reproductive Health Department Section Editor
The discovery of contraceptive genetic factors is an exciting area that researchers are currently exploring at the National Institute of Health (NIH). In fact, research into new contraceptive techniques, funded by the NIH, stumbled upon an exciting gene commonly found in mammals. Arrest domain containing 5 (ARRDC5) is a known gene that controls the last step of sperm maturation. In the study, the researchers analyzed testicular tissue from a variety of animals (cattle, pigs, and mice) and found a similar gene in the ARRDC5 family. The gene was only expressed in the testicles and nowhere else along the reproductive tract. On the same note, they made the observation that the gene was not expressed in male mice that didn’t produce the germ cells needed to produce sperm, indicating that this gene is dependent on germ cell presence.
Throughout their experiment, they observed the reproduction of ARRDC5-lacking male mice with their female counterparts and found that there were zero pregnancies. Mice lacking the gene had normally developed testes, but had a significant reduction in their overall sperm production (28% decrease) and the produced sperm moved 2.8 times slower than their ARRDC5-containing male mice counterparts.
The primary finding was that the sperm head was unable to undergo the acrosome reaction, which is when the sperm’s head fuses with the egg to form the beginning of a zygote. Due to these aforementioned reasons, researchers have identified this gene as a potential contraceptive target for future research as inhibiting this gene could yield a reversible birth control agent for men that doesn’t affect testosterone. The most fundamental realization this study gave to researchers is bifold: there is a plethora of mammalian genetics that is yet to be studied and these genes have the potential to produce a major contribution to reproductive medicine
References
Giassetti, MI, et al. ARRDC5 expression is conserved in mammalian testes and required for normal sperm morphogenesis. Nature Communications. 2023.
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