A research team found two proteins responsible for taste may also affect something further south.

In the study, mice that were missing two taste proteins were unable to produce offspring, a Monell Center press release stated.

"This paper highlights a connection between the taste system and male reproduction," lead author Bedrich Mosinger, MD, PhD, a molecular biologist at Monell said. "It is one more demonstration that components of the taste system also play important roles in other organ systems."

The proteins in question were TAS1R3, which is involved in the sweet and umami taste receptors, and GNAT3 which converts oral taste receptor signals into nerve cell responses.

Only male mice's fertility was affected by the absence of the two proteins. The substances had been found in male testes and sperm in the past, but scientists were unsure of their function.

The study engineered mice to possess the human TAS1R3 receptor, but to lack both mouse-versions of the proteins.

The team added clofibrate , a drug that blocks the protein, to the mice's diet. When on the drug the mice were sterile, they were not able to produce as much sperm and what they could produce was malformed. Their sperm count returned to normal as soon as the drug was removed from their diet.

The drug used to block the protein was a fibrate, which is a common treatment for people suffering from lipid disorders; it inhibits the human TAS1R3 receptor.

The study showed these medications could be causing a worldwide reduction in male fertility levels.

"If our pharmacological findings are indeed related to the global increase in the incidence of male infertility, we now have knowledge to help us devise treatments to reduce or reverse the effects of fibrates and phenoxy-compounds on sperm production and quality. This knowledge could further be used to design a male non-hormonal contraceptive," Mosinger said.