FIGURE 1.

Aging‐related phenotypic features of small intestinal and liver from progeroid Ercc1^{Δ /−} mice. (a) Intestinal tissue from 15‐week‐old Ercc1^{Δ /−} and control mice stained with haematoxylin and eosin. Bars 200 μm. (b, c) Intestinal length (b, n = 2) and perimeter (c, n = 4) from 15‐week‐old mice of indicated genotypes. (d) Jejunal crypt density of 15‐week‐old wt and mutant mice. Crypts were counted on paraffin‐embedded 4μm slices of intestinal tissue. The number of crypts of progeroid Ercc1^{Δ /−} mice is not significantly reduced in spite of the overall cachexia and decreased organ size, p = 0.7328 (n = 3). (e) Cell density in jejunal crypts of 15‐week‐old wt and Ercc1^{Δ /−} mice. Cells were counted on DAPI stained 4μm intestinal tissue slices as in (d), p = 0.5415 (n = 3 mice). (f) Immunofluorescent images of small intestine crypt and villi from sections stained for apoptosis (TUNEL), counterstained with DAPI. Bars 50 μm. (g, h) Apoptosis index in crypts (g) and villi (h), (n = 3 mice). (i) Liver tissue from 15‐week‐old Ercc1^{Δ /−} and wt mice assessed for apoptosis (TUNEL). Red arrows: TUNEL⁺ cells; black cut‐out depicts a TUNEL⁺ large hepatocyte. Bars 100 μm. (j–m) Apoptosis index in the liver, parenchymal, non‐parenchymal (l), and biliary cell (m) population of 15‐week‐old wt and mutant mice (n = at least 3 mice for WT, n = 5 mice for mutant groups). Quantification of TUNEL⁺ nuclei was performed on DAB‐stained liver sections. Data: mean ± SEM. *p < 0.05, **p < 0.01