Fig. 1.

Expression levels of SOX9 and insulin-like growth factor binding protein (IGFBP)-4 are coordinately regulated in mouse intestinal epithelium in vivo. A: quantification by real-time RT-PCR of Sox9 and Igfbp-4 mRNA in intestinal epithelial crypt cells from 3-mo-old Sox9-deficient mice and their littermate controls. After normalization with 18S rRNA, results are shown as expression levels relative to expression levels in wild-type mice (n = 3). *P < 0.05; **P < 0.01. B: Western blot for SOX9 and IGFBP-4 of intestinal epithelial crypt cells from Sox9-deficient mice and their littermate controls. C and D: representative images of SOX9 and IGFBP-4 immunostaining of the small intestine (top) and colon (bottom) of a wild-type (left) and a Sox9-deficient (right) mouse. Arrows show representative IGFBP-4-positive cells.