MCTP1 is expressed in TRPM5 cells.

<p>Expression of MCTP1 in LE, FG TB, and CV TB (A) as well as top and bottom portions of CV TB (B) by microarray analyses. * p<0.005 compared to LE (A) or CV TB bottom (B). Expression units are GC-RMA normalized average intensities of microarray signals. Double label <i>in situ</i> hybridization (ISH) for MCTP1 and TRPM5 (C–H). MCTP1 (C, F) and TRPM5 (D, G) are expressed in similar cells in the merged images (E, H). Double label ISH for MCTP1 and PKD1L3 (I–N). MCTP1 (I, L) and PKD1L3 (J, M) are expressed in different cells in the merged images (K, N). Single taste buds are illustrated in F–H and L–N. Scale bar is 30µm in E and represents scale for C–E and I–K. Scale bar is 25µm in H and represents scale for F–H and L–N. Images are from primate CV papilla. O, Pie chart illustrating fraction of cells expressing MCTP1, TRPM5, or both MCTP1 and TRPM5. Cells with only TRPM5 signals may contain MCTP1 transcripts below the detection limit of ISH. P, Pie chart illustrating fraction of cells expressing MCTP1, PKD1L3, or both MCTP1 and PKD1L3.</p

MCTP1 is expressed in TRPM5 cells in mouse.

<p>Double label <i>in situ</i> hybridization (ISH) for MCTP1 and TRPM5 (A–F). MCTP1 (A, D) and TRPM5 (B, E) are expressed in similar cells in the merged images (C, F). Double label ISH for MCTP1 and PKD2L1 (G–L). MCTP1 (G, J) and PKD2L1 (H, K) are expressed in different cells in the merged images (I, L). Images in D–F and J–L depict single taste buds at higher magnification. Scale bar is 40µm in C and represents scale for A–C and G–I. Scale bar is 25µm in F and represents scale for D–F and J–L. Images are from mouse CV papilla. M, Pie chart illustrating fraction of cells expressing MCTP1, TRPM5, or both MCTP1 and TRPM5. N, Pie chart illustrating fraction of cells expressing MCTP1, PKD2L1, or both MCTP1 and PKD2L1.</p

ANO7 is expressed in TRPM5 cells in mouse.

<p>Double label <i>in situ</i> hybridization (ISH) for ANO7 and TRPM5 (A–F). ANO7 (A, D) and TRPM5 (B, E) are expressed in similar cells in the merged images (C, F). Double label ISH for ANO7 and PKD2L1 (G–L). ANO7 (G, J) and PKD2L1 (H, K) are expressed in different cells in the merged images (I, L). Images in D–F and J–L depict single taste buds at higher magnification. Scale bar is 40µm in C and represents scale for A–C and G–I. Scale bar is 10µm in F and represents scale for D–F and J–L. Images are from mouse CV papilla. M, Pie chart illustrating fraction of cells expressing ANO7, TRPM5, or both ANO7 and TRPM5. N, Pie chart illustrating fraction of cells expressing ANO7, PKD2L1, or both ANO7 and PKD2L1.</p

Genes encoding transmembrane proteins are expressed in human CV taste buds.

<p>Section of human CV papilla before (A) and after (B) laser capture microdissection of taste buds. Collected taste bud regions (C), were isolated from CV papilla and used for molecular analysis of gene expression. A laser beam was used to cut the perimeter of taste buds and physically separate them from surrounding lingual epithelium. Taste buds were next lifted away from the tissue section with an adhesive cap. Panel C is an image of six isolated taste bud regions, devoid of surrounding lingual epithelium and connective tissue, on the adhesive cap. Scale bar is 40µm. Semi-quantitative PCR (D) for known taste genes (TRPM5 and PKD2L1), genes predicted or known to encode transmembrane proteins, and the housekeeping gene GAPDH in isolated CV taste buds (black bars) or non-gustatory lingual epithelium (white bars) collected by laser capture microdissection. Relative expression is shown on a logarithmic scale.</p

TMEM44 is not expressed in sweet, bitter, umami, and sour cells.

<p>Expression of TMEM44 in LE, FG TB, and CV TB (A) as well as top and bottom portions of CV TB (B) by microarray analyses. * p<0.05 compared to LE. Expression units are GC-RMA normalized average intensities of microarray signals. Double label <i>in situ</i> hybridization (ISH) for TMEM44 and TRPM5 (C–E and I–K). TMEM44 (C, I) and TRPM5 (D, J) are expressed in different cells in the merged images (E, K). Identical results were obtained in CV (C–E) or FG taste buds (I–K). Double label ISH for TMEM44 and PKD1L3 (F–H and L–N). TMEM44 (F, L) and PKD1L3 (G, M) are expressed in different cells in the merged images (H, N). Identical results were obtained in primate CV (F–H) or FG taste buds (L–N). Scale bar is 30µm in C and represents scale for C–H. Scale bar is 20µm in K and represents scale for I–N. Images are oblique sections with varying orientations from primate CV papilla. O, Pie chart illustrating fraction of cells expressing TMEM44, TRPM5, or both TMEM44 and TRPM5. P, Pie chart illustrating fraction of cells expressing TMEM44, PKD1L3, or both TMEM44 and PKD1L3.</p

ANO7 is expressed in TRPM5 cells.

<p>Expression of ANO7 in LE, FG TB, and CV TB (A) as well as top and bottom portions of CV TB (B) by microarray analyses. * p<0.005 compared to LE (A). Expression units are GC-RMA normalized average intensities of microarray signals. Double label <i>in situ</i> hybridization (ISH) for ANO7 and TRPM5 (C–E). ANO7 (C) and TRPM5 (D) are expressed in similar cells in the merged image (E). Double label ISH for ANO7 and PKD1L3 (F–H). ANO7 (F) and PKD1L3 (G) are expressed in different cells in the merged image (H). Images are from primate CV taste buds. Scale bar is 15µm in E and represents scale for C–H. I, Pie chart illustrating fraction of cells expressing ANO7, TRPM5, or both ANO7 and TRPM5. J, Pie chart illustrating fraction of cells expressing ANO7, PKD1L3, or both ANO7 and PKD1L3.</p

TMEM44 cells localize to the bottom and sides of taste buds.

<p>Double label <i>in situ</i> hybridization (ISH) for TMEM44 and TRPM5/PKD1L3 in CV taste bud; longitudinal section (A–C). TMEM44 cells (A) are enriched towards the base and sides of taste buds whereas TRPM5/PKD1L3 cells (B) are enriched toward the center and top of taste buds. A merged image with nuclei stained blue (DAPI, C) highlights these signals in a longitudinal section. Double label ISH for TMEM44 and TRPM5 in FG taste bud; tangential section in middle of taste bud (D–F). TMEM44 cells (D) surround TRPM5 cells (E) in merged image (F). Some TMEM44 cells extend processes toward the taste pore (G–I). Double label IHC-ISH for Keratin-19 (G, IHC), TMEM44 (H, ISH) and merge (I) in CV taste bud (longitudinal section). Pink arrows track a TMEM44 cell process towards the taste pore. Double label ISH for TMEM44 (blue) with TRPM5 (red) (J), SHH (blue) with TRPM5 (red) (K), and SHH (blue) with TMEM44 (red) (L) in primate CV taste buds (longitudinal sections). Small white arrows denote cells that express both TMEM44 and SHH transcripts, whereas small red arrows denote cells that express only TMEM44 transcripts. Large arrows denote taste pore region. Note that TMEM44 stain in panel A is a colorimetric signal (DIG-labeled ISH probe) that is pseudocolored green, whereas the TMEM44 stain in panel H is a fluorescent signal (FITC-labeled ISH probe). Colorimetric signals highlight the nuclear envelope and cytoplasm whereas fluorescent signals highlight intranuclear regions. Scale bar is 20µm in C and represents scale for A–L.</p