Richard Evans, Catrin Pritchard and their colleagues at GlaxoWellcome discovered a way of blocking the path of sperm from the testes, which could produce semen that is virtually sperm free without the need for an irreversible vasectomy.
On the other hand, as it were, the control they have discovered could also be used to enhance the movement of sperm from the testes and so may have potential in male fertility treatment too.
I often wonder with these fertility researcher people whether they do their research manually…maybe not. For more on male fertility research check out the sperm tap article over on Reactive Reports.