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Fig. 7 Fxr regulates differentiation and functions of anterior absorptive enterocytes in zebrafish.(A) FACS analysis comparing the relative abundance of anterior enterocytes in 7-dpf fxr+/+ and fxr−/− larvae expressing the Tg(-4.5fabp2:DsRed) and TgBAC(cldn15la-GFP) transgenes. The relative abundance was calculated by dividing the cell counts of DsRed+GFP+ double-positive cells by the cell counts of GFP+ single-positive cells (mean ± SEM). Statistical significance was calculated by unpaired t test. Representative data from two independent experiments are shown. (B) Comparisons between the genes that were differentially expressed in fxr−/− cells relative to fxr+/+ cells in cluster 4 and the mouse genes enriched in jejunal enterocytes/intestinal stem cells (ISCs) (49). Left: Venn diagram showing the number of overlapped genes between the two gene sets, of which the differentially expressed genes in fxr−/− cells were further classified based on the changes in their expression (up- or down-regulated) upon fxr mutation. Middle: Distributions of enterocyte- and ISC-enriched genes from the enterocyte/ISC dataset used in the current comparison. Right: Distribution of overlapped genes resulting from the comparison. (C) Top 3 HOMER-identified motifs enriched within accessible chromatin regions near genes that were down-regulated in the fxr−/− cells relative to fxr+/+ cells in cluster 4. The position weight matrices (PWMs) of the enriched nucleotide sequences are shown. The TF family that most closely matches the motif is indicated above the PWM.