Fig. 7

Potential model of the SNP regulation of human bitter taste perception. In vitro analysis has shown that quinine can be detected by bitter taste receptors T2R4, -7, -10, -14, -31, -39, -40, -43, and -46, and caffeine can be detected by the T2R7, -14, -43, and -46 (as summarized in Table 3), which overlap the T2Rs for quinine. Here we assume that each T2R is regulated by a major SNP with the corresponding number (e.g. SNP 4 for T2R4) and the top SNP for each taste is in linkage disequilibrium with the major SNPs for T2Rs that can detect the taste. Therefore, rs10772420 is associated with the perception of quinine via correlated SNPs, SNP 4, -7, -10, -14, -31, -39, -40, -43, and -46, and rs2597979 is associated with the perception of caffeine via correlated SNPs, SNP 7, -14, -43, and -46