DENATONIUM BITTER-TASTING AMONG TRANSGENIC MICE EXPRESSING RAT VON EBNERS GLAND PROTEIN

Von Ebner's gland protein (VEGP) is a secretory protein, which is abun dantly expressed in the small von Ebner's salivary glands of the tongu e. VEGP as component of the perireceptor environment around taste papi llae might function as transporter of hydrophobic molecules, for examp le bitter substances. Here we report a new approach to investigate the physiological role of VEGP by expression of the cloned rat VEGP gene in transgenic mice. Taste papillae of mice, in contrast to rats, do no t contain VEGP. The founder mouse 4345 and three offspring carry the t ransgene as shown by PCR analysis and saliva of the transgenic mice co ntains high amounts of VEGP. In two-bottle preference tests, transgeni c and nontransgenic siblings show significantly different capabilities to taste the bitter compound denatonium benzoate at 10 mu M. The redu ced sensitivity of transgenic mice to denatonium benzoate points to a clearance function of VEGP the specificity of which for taste compound s and other molecules remains to be seen.