Figure 3

Lack of RB stimulates enterocytes, goblet, enteroendocrine and Paneth cells. Representative sections of duodenum from RB^+/+ (A, D, G), RB^+/- (B, E, H) and RB^-/- (C, F, I) newborn pups were stained with Alkaline phosphatase (A, B, C), Alcian blue (D, E, F) and IHC using anti-serotonin antibody (G, H, I). Nuclear fast red was used as a counterstain for AP and Alcian blue staining. The quantified activity of Alkaline phosphatase was measured by the density of image (J). Alcian blue positive cells (K) or serotonin positive cells (L) were counted in 100 villi derived from RB^+/+, RB^+/- and RB^-/- intestines. Small intestine from newborn pups was subjected to RT-PCR using primers specific to cryptdin-1 and actin as a control (M). The amount of cryptdin-1 was evaluated through the density of signal (N).