Taste function in mice with a targeted mutation of the pkd1l3 gene

Recent studies, both in vitro and in vivo, have suggested the involvement of the polycystic kidney disease-1 and -2 like genes, Pkd1l3 and Pkd2l1, in acid taste transduction. In mice, disruption of taste cells expressing PKD2L1 eliminates gustatory neural responses to acids. However, no previous data exist on taste responses in the absence of PKD1L3 or on behavioral responses in mice lacking either of these proteins. In order to assess the function of PKD1L3, we genetically engineered mice with a targeted mutation of the Pkd1l3 gene. We then examined taste responsiveness of mutant and wild-type mice using several different approaches. In separate groups of mice, we measured preference scores in 48-h 2-bottle tests, determined NaCl or citric acid taste thresholds using a conditioned taste aversion technique, and conducted electrophysiological recordings of activity in the chorda tympani and glossopharyngeal nerves. Multiple taste compounds representing all major taste qualities were used in the preference tests and nerve-recording experiments. We found no significant reduction in taste responsiveness in Pkd1l3 mutant mice in behavioral or electrophysiological tests when compared with wild-type controls. Therefore, further studies are needed to elucidate the function of PKD1L3 in taste bud cells.