Reversible contraceptive slows sperm

Scientists have discovered a small molecule that prevents male mice from siring pups. The effects of this nonhormonal compound, known as CDD-2807, are reversible. Once the mice were off the compound, they were able to sire pups again. CDD-2807 targets serine/threonine-protein kinase 33 (STK33), an enzyme that's enriched in testes. Because mutations in the gene that codes for STK33 have been linked to sterility in human men, the scientists hope CDD-2807 will lead to birth control that men can use . A team led by Baylor College of Medicine's Martin M. Matzuk screened billions of potential STK33 binders using DNA-encoded libraries . After finding an initial hit, the researchers changed the molecule's structure until they arrived at CDD-2807, a compound that can inhibit STK33 at low nanomolar levels ( Science 2024, DOI: 10.1126/science.adl2688 ). When injected into the abdomens of male mice, CDD-2807 proved to be a potent contraceptive. "I