Honda-laboratory members

Members of Tomooka laboratory at the Tokyo University of Science. K. Kuroiwa, S. Watanabe, Dr. K. Honda (arrowhead, first author), T. Okumura, M. Kawada, K. Kakefuda, K. Harada, T. Ito, K.Konno (L-R, top row), M. Hoshino, T. Ishii, M. Nogimura, R. Takashina, Y. Sakai, K. Tsuruyama, R. Yamanaka, A. Ootsu, M. Kozuma (L-R, middle row), Dr. T. Nakajima, Prof. Y. Tomooka (arrow), Prof. JA. McLachlan (the Tulane University School of Medicine), Mrs. McLachlan, Prof. K. Shimizu (Shimizu laboratory at the Tokyo University of Science), A. Imai (L-R, front row).

Nerve-independent and ectopically additional induction of taste buds in organ culture of fetal tongues

Taste buds are chemoreceptors that function in the gustatory system. They are localized mainly in the tongue gustatory epithelium in mice. A taste bud is an aggregate of fusiform taste cells and the innervation of gustatory nerves sustains the turn-over of taste cells. The first emergence of a taste bud, however, occurs nerve-independently at embryonic days, and fetal tongues in organ culture (without innervation) never develop taste buds.

To challenge this inconsistency, the present study planned to establish a new organ culture method to develop the morphogenesis of taste buds. In brief, fetal tongues were embedded in collagen gel drops for a longer culture period (6 days) and a GSK3b inhibitor was added into culture medium. Non-gustatory epithelium in addition to gustatory epithelium did develop taste bud-like aggregates of taste cells in vitro. The GSK3b inhibitor is known to activate Wnt/b-catenin signaling, suggesting that the activation of the signaling plays a key role in taste bud morphogenesis without innervation. The results from the in vitro system stimulate further analysis on the gustatory sensation and the developmental mechanisms of taste buds.

Kotaro Honda, Yasuhiro Tomooka. Nerve-independent and ectopically additional induction of taste buds in organ culture of fetal tongues.  In Vitro Cellular & Developmental Biology-Animal 52:911-919, 2016