Fig. 13.

Brush lineage cells in crypts from Gfi1b^EGFP/+ mice are Neurog3⁻ and Atoh1⁻. (A) and (B) are different optical sections of the same crypt showing a proliferating (Mki67⁺) brush lineage cell (boxed) that is negative for Neurog3. The Neurog3⁺ cells (arrow heads) in (B) are ${\text{EGFP}}_{\mathit{Gfi}\mathit{1}b}^{-}$. (C, D) Proliferating (Mki67⁺) and (E) post-mitotic (Mki67⁻) brush lineage cells (boxed) are Atoh1⁻. Atoh1⁺ cells (barbed arrow heads) do not express EGFP_Gfi1b.