Variation in bitter receptor mRNA expression affects taste perception

Do you love chomping on raw broccoli while your best friend can't stand the healthy veggie in any form or guise? Part of the reason may be your genes, particularly your bitter taste genes.

Over the past decade, scientists at the Monell Center and elsewhere have made headway in understanding how variants of bitter genes can help account for how people differ with regard to taste perception and food choice.

However, some perplexing pieces of the puzzle remained, as two people with exactly the same genetic makeup can still differ markedly regarding how bitter certain foods and liquids taste to them.

Now, findings from Monell reveal that a person's sensitivity to bitter taste is shaped not only by which taste genes that person has, but also by how much messenger RNA – the gene's instruction guide that tells a taste cell to build a specific receptor – their cells make.

Under normal circumstances, people whose make more messenger RNA (mRNA) for a given gene make more of the encoded receptor.

The findings add a new level of complexity to our understanding of the of taste perception, which may ultimately lend insight into individual differences in food preferences and .

"The amount of messenger RNA that choose to make may be the missing link in explaining why some people with 'moderate-taster' genes still are extremely sensitive to bitterness in foods and drinks," said Monell taste geneticist Danielle Reed, PhD, who is an author on the study.

In the study, reported online in the American Journal of Clinical Nutrition, small biopsies of papillae – the little bumps on the tongue that contain taste receptors – were taken from 18 people known to have the same moderate-taster (heterozygous) genotype for the TASR38 bitter taste receptor and the amount of mRNA expression for this genotype was measured.

Before the biopsy, people rated the intensity of various bitter and non-bitter solutions, including broccoli juice. Even though the subjects had the same 'middle-of-the road' genotype, their responses to some of the bitter substances varied over four orders of magnitude. Analyses revealed a direct relationship between mRNA expression and bitterness ratings of broccoli juice, with subjects having the most mRNA rating the juice as most bitter.

"The next step involves learning more about what causes these individual differences in mRNA expression; does diet drive expression or is it the reverse? And, can differences in expression explain why children are more sensitive to bitter than adults with the same genotype?" said co-author Julie Mennella PHD, a developmental psychobiologist at Monell.

add to favorites email to friend print save as pdf

Related Stories

Improving medicine acceptance in kids: A matter of taste

Jul 24, 2013

Despite major advances in the pharmaceutical treatment of disease, many children reject medicines due to an aversion to bitter taste. As such, bitterness presents a key obstacle to the acceptance and effectiveness of beneficial ...

Multiple genes manage how people taste sweeteners

Aug 20, 2013

Genetics may play a role in how people's taste receptors send signals, leading to a wide spectrum of taste preferences, according to Penn State food scientists. These varied, genetically influenced responses may mean that ...

The taste of quinine: It's in your bitter genes

Aug 02, 2010

Some people find quinine to be bitter while others can drink it like water. Now, scientists from the Monell Center and collaborators report that individual differences in how people experience quinine's bitterness are related ...

Food peptides activate bitter taste receptors

Jan 22, 2008

Researchers from the Monell Center and Tokyo University of Agriculture have used a novel molecular method to identify chemical compounds from common foods that activate human bitter taste receptors.

How do you stop tasting?

Aug 02, 2011

New findings may lend insight into why some people are especially sensitive to bitter tastes. Scientists from the Monell Center and Givaudan Flavors have identified a protein inside of taste cells that acts to shorten bitter ...

Recommended for you

Stem cells faulty in Duchenne muscular dystrophy

17 hours ago

Like human patients, mice with a form of Duchenne muscular dystrophy undergo progressive muscle degeneration and accumulate connective tissue as they age. Now, researchers at the Stanford University School of Medicine have ...

Here's how the prion protein protects us

22 hours ago

The cellular prion protein (PrPC) has the ability to protect the brain's neurons. Although scientists have known about this protective physiological function for some time, they were lacking detailed knowledge ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.