Fig. 3

Genes in the epidermal differentiation complex (EDC) are under microbial regulation. a The mean relative expression of genes found in the EDC in SPF compared to GF mice. A value of 1 indicates equal expression in the two groups. Colors of the bars indicate DEGs, and error bars represent propagated SE of the ratio SPF/GF. EDC genes are grouped as previously described [35]. b Boxplot of normalized gene expression of differentially expressed transcription factors and regulators critical to skin developmental processes. c–f Histology and immunofluorescence staining of SPF and GF skin sections. Dotted line inset boxes indicate the area that is magnified in the figure to orient the reader. White arrowheads are examples of positive cells. Significance testing was performed on an aggregate of three experiments with 3 GF and 3 SPF mice each. A * indicates a p value < 0.05 by T test. Scale bars represent 50 μm. c Hematoxylin and eosin staining and epidermal thickness measurements. d Cytokeratin 6A (K6A) staining. e Ki67 staining for proliferating cells. f Loricrin staining as a marker of differentiation