Tas2r131 is a type 2 taste receptor, belonging to the large family of G protein-coupled receptors. It is primarily involved in recognizing bitter-tasting compounds, which are often aversive to vertebrates. The Tas2r131-mediated bitter taste perception is part of the body's defense mechanism against potentially harmful substances [1]. Genetic models, such as gene-targeted mice, are valuable tools for studying Tas2r131 as they allow for the manipulation and visualization of Tas2r131-expressing cells in vivo [1].

In gene-targeted mouse studies, the generation of Tas2r131-specific Cre knock-in mouse strains has enabled the visualization of Tas2r131-expressing cells in gustatory and nongustatory tissues. These cells were found in several nongustatory tissues like lung, trachea, ovary, ganglia, and brain, as well as in taste buds, mainly in foliate and vallate papillae. A subset of colonic goblet cells, deep-crypt Paneth cells in the ileum, cholinergic cells in the thymic medulla, and cells in tracheal and laryngeal glandular ducts also express Tas2r131. Additionally, Tas2r131 was identified among the receptors in the mouse Grueneberg ganglion involved in detecting danger-related volatile compounds [1,2,3,4,5,6].

In conclusion, Tas2r131 plays a crucial role in bitter taste perception, which is important for the body's defense against harmful substances. The use of KO/CKO mouse models has revealed its presence and potential functions in various gustatory and nongustatory tissues, suggesting its involvement in multiple physiological processes, although further research is needed to fully understand its implications in disease conditions.

References:

1. Voigt, Anja, Hübner, Sandra, Döring, Linda, Boehm, Ulrich, Meyerhof, Wolfgang. 2015. Cre-Mediated Recombination in Tas2r131 Cells-A Unique Way to Explore Bitter Taste Receptor Function Inside and Outside of the Taste System. In Chemical senses, 40, 627-39. doi:10.1093/chemse/bjv049. https://pubmed.ncbi.nlm.nih.gov/26377344/

2. Soultanova, Aichurek, Voigt, Anja, Chubanov, Vladimir, Boehm, Ulrich, Kummer, Wolfgang. 2015. Cholinergic chemosensory cells of the thymic medulla express the bitter receptor Tas2r131. In International immunopharmacology, 29, 143-7. doi:10.1016/j.intimp.2015.06.005. https://pubmed.ncbi.nlm.nih.gov/26102274/

3. Prandi, Simone, Bromke, Marta, Hübner, Sandra, Meyerhof, Wolfgang, Behrens, Maik. 2013. A subset of mouse colonic goblet cells expresses the bitter taste receptor Tas2r131. In PloS one, 8, e82820. doi:10.1371/journal.pone.0082820. https://pubmed.ncbi.nlm.nih.gov/24367558/

4. Prandi, Simone, Voigt, Anja, Meyerhof, Wolfgang, Behrens, Maik. 2017. Expression profiling of Tas2r genes reveals a complex pattern along the mouse GI tract and the presence of Tas2r131 in a subset of intestinal Paneth cells. In Cellular and molecular life sciences : CMLS, 75, 49-65. doi:10.1007/s00018-017-2621-y. https://pubmed.ncbi.nlm.nih.gov/28801754/

5. Moine, Fabian, Brechbühl, Julien, Nenniger Tosato, Monique, Beaumann, Manon, Broillet, Marie-Christine. 2018. Alarm pheromone and kairomone detection via bitter taste receptors in the mouse Grueneberg ganglion. In BMC biology, 16, 12. doi:10.1186/s12915-017-0479-y. https://pubmed.ncbi.nlm.nih.gov/29347925/

6. Krasteva-Christ, G, Soultanova, A, Schütz, B, Weihe, E, Kummer, W. 2015. Identification of cholinergic chemosensory cells in mouse tracheal and laryngeal glandular ducts. In International immunopharmacology, 29, 158-65. doi:10.1016/j.intimp.2015.05.028. https://pubmed.ncbi.nlm.nih.gov/26033492/