We all perceive the tastes of certain foods differently. You may find specific food disgusting, while your brother or sister finds it delicious (brussel sprouts for instance). Researchers from the University of Pennsylvania have recently done a new study, finding a genetic mutation that makes certain people more sensitive to the taste of a bitter compound, which could have been very beneficial for certain humans in Africa. Because of this, the gene mutation has been passed from generation to generation due to the fact that Africa is the origin of all modern humans. This study represents the first time that the bitter-sensitivity gene, known as TAS2R16, has been studied in such a large set of ethnically diverse African populations. The new study was built on previous research that looked at the evolutionary history of the TAS2R16 gene, which allows humans to sense the bitter taste. This recent study examined the TAS2R16 gene that codes for a receptor that attaches to salicin, a naturally found bitter compound (in willow bark and source of aspirin). Salicin is an anti-inflammatory and can be found in many nuts, fruits, and vegetables.
This new study sampled DNA from about 600 people in 74 populations across Africa with many different kinds of lifestyles. The researchers then sequenced the TAS2R16 gene in all of the Africans as well as 94 non-Africans for comparison. They were able to identify 15 variants of the gene, most only found in Africa. About 300 of the Africans also performed a taste test of different concentrations of salicin, expressing when they could detect the "bitter" taste. This taste test showed that the TAS2R16 gene caused a gain of taste function. When the researchers matched the individuals' genetic profiles with their taste testing performance, they discovered that there was a strong connection between one of the variants and an increased sensitivity to salicin. Cellular analysis also showed that the individuals with this particular genetic variant had almost twice as many receptors for salicin than those with other forms of the TAS2R16 gene. The high-sensitivity variant was most common in people from East Africa (not West or Central Africa), which indicates an evolutionary change. Non-Africans were found to only have the high-sensitivity version of the gene. For the future researchers hope this study can start giving us clues as to what we should look at in terms of the bio medical and physiological significance of these genes.
I chose this article because I find it interesting how some people can like certain tastes while others do not. This helped me understand where exactly the bitter tasting gene comes from and how it works. This was very informative and I think it will help researchers with future studies of taste buds.
Article: http://www.redorbit.com/news/science/1113000905/genetic-mutation-bitter-taste-human-evolution-111213/
Link: https://www.23andme.com/health/Bitter-Taste-Perception/
I find this very interesting. I always thought that we taste bitter things just because that was the way our taste buds worked. I didn't think it was because there was a mutation that caused the human race such a long time ago to start to taste things that were bitter. I think this is very interesting because then it poses me to ask: is that how we taste sweet and salty and sour things too? Was there some type of mutation somewhere in history that caused us to taste those drastically different tastes? I wonder if that is possible! Very cool!
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