Figure 2

Distribution of apolipoprotein A-II mRNA and protein in the mouse fetal lung. Mouse tissue sections are from pseudoglandular (GD 15.5: a-b, g), junction between pseudoglandular and canalicular (GD 16.5: d), late canalicular (GD 17.5: c, e-f, h-k), or early saccular (GD 18.5: l-m) stages. In situ hybridization (within blue frames) (a-f) was performed with apoA-II anti-sense (a-e) and sense (f) probes. Positive signal is blue. A change in sites of apoA-II gene expression was observed according to gestation time. Immunohistochemistry (within red frames) (g-m) was performed using an anti-apoA-II polyclonal antibody (g-h, j-m) or goat IgG as negative control (i). Positive signal (red) was found in the mesenchyme. Some mesenchymal cells presented a stained nucleus between GD 15.5 and GD 17.5. Positive signals were also observed on capillaries. GDs are indicated on photographs. Dashed frames, negative controls. Scale bars, 50 μm (a, c-d, f-i, k-l) or 20 μm (b, e, j, m). C, capillaries; D, distal epithelium; M, mesenchyme; N, positive nuclei; P, proximal epithelium.