Figure 1
CCR7−/− mice frequently develop an anorectal prolapse, exhibit reduced whole-gut transit time, and enhanced colonic lymphoid aggregates. (a) In all, 34% of CCR7−/− mice (dotted line; n=50) developed a severe anorectal prolapse within 2–12 months of age. Only 1 out of 35 wild-type (Wt) mice (straight line) developed an anorectal prolapse at 11 months of age. (b) Whole-gut transit time was reduced in CCR7−/− (open bars; n=5) compared with Wt (black bars; n=5) mice. One representative experiment of two independent experiments is shown. Bars represent means±s.d. **P<0.01; Mann–Whitney test. (c) Impedance spectroscopy revealed a higher subepithelial resistance in stripped colon tissue of 10–12-week-old CCR7−/− (n=4; open bars) compared with Wt (n=6; black bars) mice. Bars represent means±s.e.m. *P<0.05; unpaired Student's t test. (d) Paraffin-embedded sections of the large intestine of 8–12-week-old Wt or CCR7−/− mice (n=6–7 per group) were stained with hematoxylin and eosin (H&E; one representative animal of each group is shown). Bar=100 μm. (e) The number of colonic isolated lymphoid follicles (ILFs) was quantified based on two sections of each animal (Wt: black squares, n=8; CCR7−/−: open circles, n=8; left panel) and total numbers of colonic lamina propria (LP)–derived CD45+ leukocytes were quantified by flow cytometry (Wt: black squares, n=3; CCR7−/−: open circles, n=3; right panel). *P<0.05, ***P<0.001; Mann–Whitney test.
