Figure 1.

Sca-1 and CD34 expression in the lung. (A): Flow cytometry analysis of Sca-1 and CD34 expression on the cell surface of CD45^neg CD31^neg live single-cell preparations from mouse lung (parameters used for initial selection of cells to be interrogated are given in supporting information Fig. 1). Panels represent unstained control (upper left), Sca-1-stained sample (upper right), CD34-stained sample (lower left), and Sca-1- and CD34-stained sample (lower right). Gates identify populations as follows: R1, CD34-positive population; R2, Sca-1 and CD34 dual-positive population; R3, Sca-1^low population; R4, Sca-1^high population. Unstained sample: R1 = 0.27%, R2 = 0.00, R3+R4 = 0.17%; Sca-1-stained sample: R1 = 0.14%, R2 = 0.01%, R3 = 18.3, R4 = 5.33%; CD34-stained sample: R1 = 12.11%, R2 = 0.00%, R3 = 0.38%, R4 = 0.00%; Sca-1 CD34 dual-stained sample: R1 = 2.75%, R2 = 6.07%, R3 = 11.94%, R4 = 0.30%. (B): Quantitative representation of data in (A). Data represent averages with SEM for seven samples from three separate experiments. Data represent percentage of live CD45^neg CD31^neg population: R1 = 3.1%, R2 = 4.62%, R3 = 14.34%, R4 = 0.46%. (C): Immunofluorescence staining of lung sections demonstrating the spatial localization of Sca-1-positive cells in the lung. Top row: Sca-1 (red) immunolocalization. Bottom row: overlay of Sca-1 staining with the nonciliated airway epithelial cell-specific marker CCSP (green). Images were taken at a magnification of ×200. Abbreviations: BADJ, bronchioalveolar duct junction; CCSP, Clara cell secretory protein; PE, phycoerythrin.