FIG. 3.

Cell lineages and proliferation in the jejunum of growth-impaired MTG8 exon 2-targeted mice. Jejunal sections from the mice shown in Fig. 2 were stained for markers of differentiated and proliferating cells. Sucrase-isomaltase (S/I) is a brush border enzyme characteristic of enterocytes; UEAI lectin (UEAI) binds to α-linked fucose residues in polysaccharides secreted by goblet and Paneth cells; α-smooth muscle actin (α-smAct) is present in the muscle layers of the gastrointestinal tract, as well as in vascular smooth muscle cells and myofibroblasts; β-tubulin III (β-tubIII) identifies ENS cells, and PCNA is an antigen associated with actively cycling cells. A positive reaction (brown color) was developed by the immunoperoxidase-diaminobenzidine technique, followed by counterstaining with Gill's hematoxylin. Despite the disruption of the gut architecture, the rates of cell differentiation and cell proliferation in the mutant are not significantly different from those in the control.