Comparison of the cellular components of jejunal and ileal crypts between SAMP1 and AKR mice. A, OLFM 4 staining of ISCs. B, Lysozyme staining of Paneth cells. C, Proliferating cell nuclear antigen staining of TA cells. D, EdU assay. Immunohistochemically positive and EdU-positive cells were counted in 10 intact villi or crypts selected from each intestinal segment of SAMP1 (n = 3) and AKR mice (n = 3).