Fig. 6.

MTG16 decreases stem cell regenerative response after radiation-induced injury. A: plating efficiency of intestinal crypts isolated from WT and Mtg16^−/− mice dosed with 12 Gy irradiation. Higher plating efficiencies were observed in crypts isolated from Mtg16^−/− mice compared with crypt isolation from WT mice (*P = 0.01; white arrows indicate live and black arrows indicate dead enterospheres, ×10 magnification). Experiments were performed in duplicate and repeated 3 times. B: quantitative PCR of Mtg16 expression in Sox9-EGFP^Negative, Sox9-EGFP^Sublow, Sox9-EGFP^Low, and Sox9-EGFP^High cells from the intestines of both nonirradiated and irradiated mice. No significant differences were observed in Mtg16 mRNA levels across populations. Mtg16 mRNA expression is lower in intestinal epithelial stem cell (IESC) enriched Sox9-EGFP^Low and higher in terminally differentiated Sox9-EGFP^Negative cells 5 days postirradiation (IESCs: *P < 0.05; enterocytes: *P < 0.05; n = 5 per group). Black bars represent nonirradiated (NI) and white bars represents irradiated (Irr).