Figure 1

Distribution of apolipoprotein A-I mRNA and protein in the mouse fetal lung. Mouse tissue sections are from pseudoglandular (GD 15.5: a-b, f-g) or late canalicular (GD 17.5: c-e, h-k) stages. In situ hybridization (within blue frames) (a-e) was performed with apoA-I anti-sense (a-d) and sense (e) probes. Positive signals (blue) show that the site of apoA-I mRNA synthesis changes according to developmental time. Immunohistochemistry (within red frames) (f-k) was performed using an anti-apoA-I polyclonal antibody (f, h-j) or goat IgG as negative control (g, k). Positive signals (red) were mainly found on capillaries with no change in localization between GD 15.5 and 17.5. GDs are indicated on photographs. Dashed frames, negative controls. Scale bars, 50 μm (a, c, e-h, k) or 20 μm (b, d, i-j). A, artery; C, capillaries; D, distal epithelium; M, mesenchyme; P, proximal epithelium; SM smooth muscle.