Fig 1. A-D: Single-plane laser-scanning confocal photomicrographs illustrate the distribution of RFP⁺ cells in mature taste buds in young adult (8 week) P0-Cre/RFP mice.

Taste bud cells in lingual fungiform (A), foliate (B), circumvallate (C) papillae and soft palate (D) were labeled by immunoreactivity of a pan-taste cell marker Keratin 8 (Krt8, green). Tissue sections were counterstained with DAPI (blue) to stain the nuclei of all cells. White dotted lines demarcate the epithelium from underlying connective tissue with short arrows pointing to connective tissue. Green dots in A and D bracket taste buds. P0-Cre driven RFP⁺ cells were abundantly distributed in taste buds and underlying lamina propria of the tongue and soft palate. No RFP⁺ cells were seen in the surrounding epithelium (arrowheads) of taste buds. Scale bars: 20 μm for all images. E: Histogram shows the average (x̄±SD, n = 3) of RFP⁺Krt8⁺ as a proportion of total Krt8⁺ taste bud cell profiles in fungiform, foliate and circumvallate papillae in 8-week-old mice. F: Data from 3 mice for each stage (2, 4, 8 and 16 week) are represented as box plot of median±percentile. The diamond within each box represents the average (n = 3) of RFP⁺Krt8⁺ double labeled versus total Krt8⁺ taste bud cell profiles in fungiform papillae at different stages.