It's every bloke's secret nightmare, until you have your own little sprogs that is, that once you actually get down to it, you might be a little, well, anaemic in the baby-making department. Now it seems if you have a weak sense of taste, your little soldiers might be a bit crap.
The discovery, probably made by complete accident like most of these weird things normally are, revolves around one particular cellular signalling pathway called Notch. You see, the Notch signalling pathway, or more specifically the Tas1r3 receptor that's normally involved in your sense of taste for both sweet and umami, was found in testicles and sperm too.
Researchers attempting to breed mice with taste deficiencies, inserted the human TAS1R3 gene into the mouse genome and then used drugs to inhibit its fuction. What they found was that during the course of the drug treatment, which knocked out the receptor, the male mice achieved the desired lack of taste but were also rendered infertile. It seems the receptor is involved somewhere in the production of healthy sperm, precisely at which point is as yet unknown. Most of the mouse sperm didn't make it to maturity, and those that did were badly deformed.
In mice is one thing, but the human implications of this are quite big. Given that there are drugs currently on the market that specifically target the TAS1R3 receptor for the control of some metabolic diseases, as well as a herbicide that does a similar job, it could be one factor in the steadily declining male fertility. The good news is that once the drug treatment was removed, the fertility of the mice returned to normal within a matter of weeks.
So, if you happen to have a poor sense of taste for sweet and umami, I'm sorry to tell you but you might be firing blanks. Likewise, if you're not quite as potent as you should be, maybe we've found a reason. Once we identify these things, we can normally do something about it, which is good news for both you and your potential kids. [PNAS via Ars Technica]