FIGURE 1.

Pulmonary aging induced by TERC or TERT deficiency. A, β-gal staining of pulmonary sections from TERC-null mice. The left and middle panels are representative micrographs of β-gal staining observed with a ×20 and ×40 objective lens. Blue arrows, positive stained cells; asterisks, alveolar sacs. The right bar graph shows the quantitative data of the β-gal staining from three animals. Data are the mean ± S.E. (error bars). B, β-gal staining of the pulmonary sections from TERT-null mice. The left and middle panels are representative micrographs of β-gal staining observed with a ×20 objective lens. Blue arrows, positive stained cells; asterisks, alveolar sacs. The right bar graph shows the quantitative data of the β-gal staining from three animals. Data are the mean ± S.E. C–E, comparisons of alveolar counts (C), alveolar sac counts (D), and total alveolar areas (E) between WT and G3 TERC-null lungs. Data are mean ± S.E. from three experiments. F–H, SA-β-gal activity in AECII was detected by flow cytometry with incubation of C12FDG and AECII markers. RU, relative units.