Limited evidence for adaptive evolution and functional effect of allelic variation at rs702424 in the promoter of the TAS2R16 bitter taste receptor gene in Africa.
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Date
2014-05-01
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Journal of human genetics
Abstract
Bitter taste perception, mediated by receptors encoded by the TAS2R loci, has important roles in human health and nutrition.
Prior studies have demonstrated that nonsynonymous variation at site 516 in the coding exon of TAS2R16, a bitter taste
receptor gene on chromosome 7, has been subject to positive selection and is strongly correlated with differences in sensitivity
to salicin, a bitter anti-inflammatory compound, in human populations. However, a recent study suggested that the derived
G-allele at rs702424 in the TAS2R16 promoter has also been the target of recent selection and may have an additional effect
on the levels of salicin bitter taste perception. Here, we examined alleles at rs702424 for signatures of selection using
Extended Haplotype Homozygosity (EHH) and F ST statistics in diverse populations from West Central, Central and East Africa.
We also performed a genotype–phenotype analysis of salicin sensitivity in a subset of 135 individuals from East Africa. Based
on our data, we did not find evidence for positive selection at rs702424 in African populations, suggesting that nucleotide
position 516 is likely the site under selection at TAS2R16. Moreover, we did not detect a significant association between
rs702424 alleles and salicin bitter taste recognition, implying that this site does not contribute to salicin phenotypic variance.
Overall, this study of African diversity provides further information regarding the genetic architecture and evolutionary history of
a biologically-relevant trait in humans.
Description
Keywords
Evolution, AS2R16, Allelic variation
Citation
Campbell, M.C., Ranciaro, A., Zinshteyn, D., Rawlings-Goss, R., Hirbo, J., Thompson, S., Woldemeskel, D., Froment, A., Omar, S.A., Bodo, J.M. and Nyambo, T., 2014. Limited evidence for adaptive evolution and functional effect of allelic variation at rs702424 in the promoter of the TAS2R16 bitter taste receptor gene in Africa. Journal of human genetics, 59(6), pp.349-352.