Fig 1.
Bitter receptor locations in the human genome.
The location of TAS2R genes on human chromosomes 5, 7, and 12 marked by red bars.
Table 1.
Penn Dermatology subject characteristics.
Table 2.
Combined subject characteristics.
Fig 2.
Quantification of skin-specific gene expression—qPCR results from cDNA of FP and skin samples.
Data are from amplification of skin-specific markers characterized in the table [14, 15]. Data from all markers are represented in order of skin layer for each individual biopsy, with the top of the epidermis (CDSN) as the lightest bar section and the bottom of the dermis (COL1A1) as the darkest bar section. Results were standardized to the housekeeping gene GAPDH and expressed as 2ΔΔCt.
Fig 3.
Results from two rounds of PCR.
Each column is labeled by a gene, with members of the TAS2R family in the order of location on human chromosomes. Each row is labeled by a sample ID, where ‘gDNA’ represents genomic DNA (positive control), 'FP' represents taste tissue, and 'W' represents water (a negative control). Green box, bands in both experiments; yellow box, bands in one experiment; red box, no bands. * indicates that there was only one PCR experiment for that gene.
Table 3.
Primer sequences.
Fig 4.
Quantification of bitter taste-related gene expression—qPCR results from cDNA of skin samples after amplification for genes of interest.
cDNA was amplified with primers for GNAT3, KRT10, and the 25 TAS2R genes. Data were standardized to the housekeeping gene GAPDH, and 2ΔΔCt was calculated. Results were plotted with individual values in gray and mean across all subjects in red (n = 9). Data points for the FP sample are in blue.
Table 4.
GTEx subject characteristics.
Fig 5.
Expression levels of TAS2R genes from RNA-seq obtained from the GTEx database.
Data are plotted with individual RPKM values in gray points and mean across all samples in red lines (N = 914).
Fig 6.
Effect of sun exposure on TAS2R expression from the GTEx data.
Expression levels of bitter receptor genes from RNA-seq obtained from the GTEx database are separated based on sun exposure. Data are plotted as mean and SD across subjects that donated both skin sample types (N = 299 for each sample type). *p<0.05, **p<0.01, ***p < 0.001; ****p < 0.0001.
Fig 7.
Effect of sex on TAS2R expression from the GTEx data.
Expression levels of bitter receptor genes from RNA-seq obtained from the GTEx database are separated based on sex and presumed sun exposure. Data are plotted as mean and SD across males (N = 603) and females (N = 311) that donated both skin sample types. *p<0.05, **p<0.01, ***p < 0.001; ****p < 0.0001.
Fig 8.
Correlation plots of TAS2R expression against age from the GTEx data.
Individual RPKM data are plotted separated by sun exposure and in order of increasing age of the subject for each receptor. R values and p values are given on the corresponding plot.