Download TAS2R38 – the gene for bitter taste perception

TAS2R38 – the gene for bitter taste perception
Do you savour a strong
cup of coffee or does
it just leave you with a
bad taste in your mouth?
Perhaps like a lot of
people you aren’t too
keen on Brussels sprouts
and broccoli. You might
have the perfect excuse
next time you’re offered
an extra helping: it’s just
not in your genes to
like certain vegetables!
Around a quarter of people, the so-called ‘super-tasters’,
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‘non-tasters’, can’t taste PROP at all. The remaining 50%
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We all perceive taste
and aroma differently.
Researchers have found
a great deal of variation
in taste sensitivity between different people. It does
appear to be highly heritable though and therefore
likely to run in families.
Having just one copy of the proline (P) amino acid means
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If you have two copies of the alternative alanine (A) amino
acid, you are more likely to be a ‘non-taster’.
TAS2R38 – the gene for bitter taste perception
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appears to be the major factor in how we respond to
bitter compounds such as PROP. This gene, named
TAS2R38, has two common forms as a result of a
single base change in the DNA code from a C to a G,
which causes an amino acid change from proline to
alanine in the resulting protein.
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Scientists use a bitter
compound known
as PROP to measure
sensitivity to bitter taste.
Although PROP is not
found in nature, it is
chemically similar to the
bitter components found
in vegetables such as
cabbage and spinach
as well as coffee, tonic
water and dark beer.
GG
AA
AP
PP
Gel Images showing the three possible versions of the
TAS2R38 gene. Which combination of bands are present in
your portrait tells us which genotype you have for this trait.
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AA
You have two copies of the alanine ‘A’ allele.
Individuals with this genotype have an approximately 80% chance of being unable
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about 20% of people with this genotype do exhibit moderate levels of bitter tasting.
This genotype is found in approximately 25% of the worldwide population although
it is much more common in those of Chinese ancestry at almost 50%.
AP
You have one copy of the alanine ‘A’ allele and one copy of the proline ‘P’ allele.
Having one copy of each allele is associated with a wide range of taste ability from
moderate taster to ‘super-taster’.
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rejection of Brussels sprouts and unpalatable medications by children may actually
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This genotype is found in approximately 50% of the worldwide population.
PP
You have two copies of the proline ‘P’ allele.
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though as despite any bitter taste the levels of toxins in green vegetables are
generally very low and they are of course extremely good for your health.
This genotype is found in approximately 25% of the worldwide population although
Southwest Native Americans have been found to be exclusively of this genotype.
Did you know…?
Our ancestors would have relied heavily upon
their sense of taste; avoiding bitter-tasting
foods that were likely to be toxic assured their
survival. However as time went on and people
began to cultivate safe ‘human-friendly’ plants,
an ability to taste bitter compounds became
less important.
TAS2R38 – the gene for bitter taste perception
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