FIGURE 4.

Intestinal epithelium-specific PGC1α knock-out mouse (PGC1α^ΔIEC) was created by mating a PGC1α^loxP/loxP mouse with a villin-cre mouse. Mice were genotyped using RT-PCR (A). Immunofluorescence for PGC1α (Cy3, red), E-cad (FITC, green), and nuclear stain (DAPI, blue) demonstrates a significant decrease of PGC1α protein within the intestinal epithelium of PGC1α^ΔIEC mice (B, n = 8/group, scale bars, 100 μm). Staining in both the colon and ileum was quantified. Representative images are provided from the colon of PGC1α^loxP/loxP mice (B, panel i) and PGC1α^ΔIEC mice (B, panels ii and iii) as well as the ileum of PGC1α^loxP/loxP mice (B, panel iv) and PGC1α^ΔIEC mice (B, panels v and vi). qRT-PCR of intestinal tissue demonstrates PGC1α expression in the colon, ileum, and liver of PGC1α^ΔIEC and PGC1α^loxP/loxP mice. Expression is decreased in the intestines of PGC1α^ΔIEC mice as compared with PGC1α^loxP/loxP mice but not in the liver (C). No differences in intestinal morphology were noted between strains (D, panels i and ii). Immunofluorescence was performed for colonic villin (D, panels iii and iv, scale bars, 100 μm), colonic Muc2 (D, panels v and vi), ileal lysozyme (D, panels vii and viii), and colonic BrdU (D, panels ix and x). When quantification was performed, no differences were noted between strains. Alcian blue staining for goblet cells was similar between strains (D, xi and xii). β diversity comparisons of microbial communities within fecal samples from PGC1α^ΔIEC mice and their PGC1α^loxP/loxP littermates are not significant. Shown are the observed species indices for each sample group (E). Displayed are principal coordinate analyses of unweighted Unifrac distances between all samples analyzed. Axis labels indicate the proportion of variance explained by each principal coordinate axis. Fecal samples of the two strains do not cluster separately within the principal coordinate space. Diversity within each group is as great as the diversity between sample types. α diversity comparisons of microbial communities within fecal samples from PGC1α^ΔIEC mice and their PGC1α^loxP/loxP littermates are not significant. Shown are the observed species indices for each sample group (F). *, p ≤ 0.05.