My husband is a big fan of chocolate. It’s the only type of dessert he wants and chocolate chip cookies or a mud pie is guaranteed to bring a big chocolaty smile to his face. However, he also suffers terribly from allergies and for at least two months out of the year he is barely able to taste a thing. Not being able to taste your favorite foods can be devastating to some people, but for men, a medical condition that hinders the body’s ability to taste food could cause even more serious issues.
A study done at the Monell Center has revealed that two proteins involved with oral taste detection are linked with the development of sperm. In taste-related exploration with mice, researchers found that mice with suppressed or absent TAS1R3 and GNAT3 molecules became infertile. TheTAS1R3 protein is a component of both the sweet and umami taste receptors, and the GNAT3 is a molecule is needed to convert the oral taste receptor signal into a nerve cell response.
The breeding experiments done after the taste molecules were found to cause infertility only affected male mice. To investigate the reproductive function of the two proteins, the researchers in the study engineered mice that were missing genes for the mouse versions of TAS1R3 and GNAT3. However, the mice also had the human form of the TAS1R3 receptor. It was found that these mice were fertile. When the human TAS1R3 was suppressed in the mice, they became infertile.
The protein was suppressed with the drug clofibrate. This drug belongs to a class of drugs called fibrates which are frequently prescribed to treat lipid disorders like high blood cholesterol or triglycerides. Researchers believe that this knowledge could provide answers to two different fertility problems. In one instance, it could potentially answer why male fertility has been steadily increasing. Before this study, researchers were unclear why the two taste proteins were also present in the testes, and now they have a link. Also, since the mice were able to reproduce normally after they were taken off of clofibrate, the drug could potentially be used to make a non-hormonal male contraception.
Monell molecular neurobiologist Robert Margolskee commented on the study saying, "Like much good science, our current findings pose more questions than answers. We now need to identify the pathways and mechanisms in testes that utilize these taste genes so we can understand how their loss leads to infertility."
- Bedrich Mosinger, Kevin M. Redding, M. Rockwell Parker, Valeriya Yevshayeva, Karen K. Yee, Katerina Dyomina, Yan Li, and Robert F. Margolskee. Genetic loss or pharmacological blockade of testes-expressed taste genes causes male sterility. PNAS, July 1, 2013 DOI:10.1073/pnas.1302827110
- Monell Chemical Senses Center (2013, July 1). Inactivation of taste genes causes male sterility. ScienceDaily.