Bitter taste signaling pathway is required for spermatogenesis and maintenance of male fertility in mice.

Recently, the expression of bitter taste receptors and their downstream taste signaling cascade have been widely found outside the gustatory system, indicating important physiological functions of bitter taste receptors in various extraoral organs including testis, but little is known about their functions in spermatogenesis. Here, we describe the localization and expression pattern of taste signaling transduction molecules in the testis. Genetic mutation of bitter signaling transduction molecules decreased the litter size, the IVF rate and the diameter of seminiferous tubules and even resulted in empty seminiferous tubules.

Genetic mutation of Tas2r104/Tas2r105/Tas2r114 cluster leads to a loss of taste perception to denatonium benzoate and cucurbitacin B.

Background: Bitter taste receptors (Tas2rs) are generally considered to sense various bitter compounds to escape the intake of toxic substances. Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.

Methods: To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues, multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.

Ablation of NTPDase2+ cells inhibits the formation of filiform papillae in tongue tip.

Background: Lingual epithelia in the tongue tip are among the most rapidly regenerating tissues, but the mechanism of cell genesis in this tissue is still unknown. Previous study has suggested the existence of multiple stem cell pools in lingual epithelia and papillae. Like K14+ and Sox2+ cells, NTPDase2+ cells have characteristics of stem cells.