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Expression of Bitter Taste Receptors in the Intestinal Cells of Non-Human Primates


Expression of Bitter Taste Receptors in the Intestinal Cells of Non-Human Primates

Hiroo Imai et al. Int J Mol Sci.


(1) Background: Recent studies have investigated the expression of taste-related genes in the organs of various animals, including humans; however, data for additional taxa are needed to facilitate comparative analyses within and among species. (2) Methods: We investigated the expression of taste-related genes in the intestines of rhesus macaques, the non-human primates most commonly used in experimental models. (3) Results: Based on RNAseq and qRT-PCR, genes encoding bitter taste receptors and the G-protein gustducin were expressed in the gut of rhesus macaques. RNAscope analysis showed that one of the bitter receptors, TAS2R38, was expressed in some cells in the small intestine, and immunohistochemical analysis revealed the presence of T2R38-positive cells in the villi of the intestines. (4) Conclusions: These results suggest that bitter receptors are expressed in the gut of rhesus macaques, supporting the use of macaques as a model for studies of human taste, including gut analyses.

Keywords: RNAseq; bitter taste receptors; macaque.

Conflict of interest statement

The authors declare no conflict of interest.


Figure 1
Figure 1
Expression levels of TAS2Rs as measured by RNAseq, which was performed using samples from the rhesus macaque duodenum (A), ileum (B), and colon (C). Each n = 3.
Figure 2
Figure 2
Expression levels of TAS2R38 (A), GNAT3 (B), and TRPM5 (C) in rhesus macaque tissue samples (n = 3) as determined by qRT-PCR. The expression levels of TAS2Rs were normalized against the expression in circumvallate papillae (CV) (set to 1) using GAPDH and beta-actin as reference.
Figure 3
Figure 3
The mRNA localization in the CV and gut, as determined by RNAscope. Probes for TAS2R38 (blue) and TRPM5 (red) were hybridized and visualized in the rhesus macaque CV (A), duodenum (B), ileum (C), and colon (D). Arrowheads indicate TAS2R38+/TRPM5+ cells. Bar = 50 µm.
Figure 4
Figure 4
Immunohistochemical detection of T2R38-positive cells in the duodenum. T2R38-positive cells were visualized by antibodies against T2R38 (green in A, D, G, J), chromogranin A (red in B), Mucin2 (red in E), DCLK1 (red in H), gustducin (red in K), and DAPI (blue) with overlay (C, F, I, L). Arrowheads indicate T2R38+/marker+ cells. Arrows indicate T2R38−/marker+ cells. Bar = 10 µm.

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