Figure 1

Immunolocalization of α ₅ nAChR subunits during periods of murine lung morphogenesis. α₅ was primarily detected in primitive respiratory epithelium at E13.5 (A, arrow) and E15.5 (B, arrow) and only minimally detected in mesenchyme (arrowheads). During the saccular stage of lung development (E18.5, C and PN1, D), α₅ was prominently located on respiratory epithelium in the larger airways (arrows). Expression of α₅ in airway epithelium was diminished at PN4 (E, arrow) and PN10 (F, arrow) and common in distal lung epithelium (arrowheads). At PN20, robust expression of α₅ was again detected throughout the proximal lung airways (G, arrow) and expression persisted in the periphery (G, arrowhead) at the completion of alveologenesis. No immunoreactivity was observed in PN20 lung sections incubated without primary antibody (H). All images are at 40X original magnification and scale bars represent 50 μm.