Leucine-rich repeat-containing G-protein coupled receptor 5-expressing
(Lgr5+) cells have been identified as stem/progenitor cells in
the circumvallate papillae, and single cultured Lgr5+ cells give rise
to taste cells. Here we use circumvallate papilla tissue to establish a
three-dimensional culture system (taste bud organoids) that develops phenotypic
characteristics similar to native tissue, including a multilayered epithelium
containing stem/progenitor in the outer layers and taste cells in the inner layers.
Furthermore, characterization of the cell cycle of the taste bud progenitor niche
reveals striking dynamics of taste bud development and regeneration. Using this
taste bud organoid culture system and FUCCI2 transgenic mice, we identify the
stem/progenitor cells have at least 5 distinct cell cycle populations by tracking
within 24-hour synchronized oscillations of proliferation. Additionally, we
demonstrate that stem/progenitor cells have motility to form taste bud organoids.
Taste bud organoids provides a system for elucidating mechanisms of taste signaling,
disease modeling, and taste tissue regeneration.