alpha-gustducin expression in the vomeronasal organ of the mouse

The expression of alpha-gustducin, a G protein alpha subunit involved in bi tter and sweet taste transduction, was investigated in chemosensory tissues of adult mice. By immunohistochemistry, alpha gustducin was absent in the olfactory neuroepithelium. Instead, alpha gustducin was expressed in a subs et of bipolar cells in the proliferative zone of the vomeronasal neuroepith elium as well as in taste buds. Northern blot analysis confirmed the presen ce of alpha gustducin in isolated vomeronasal organs. Moreover, immunohisto - chemistry revealed the expression of alpha gustducin in scattered cells o f the nasal respiratory epithelium. These results show for the first time t hat alpha gustducin is expressed in chemosensory tissue outside the aliment ary tract, suggesting that common transduction mechanisms could be shared b y apparently unrelated chemosensory tissues.