Figure 3

CAIX expression in bronchial trees and genital organs: In the bronchial trees high expression of CAIX was seen in the peribronchial immature mesenchymal cells and cartilage (designated C) (A1) but progressively diminished when the tissues became mature (A2, A3). CAIX positivity was persistently seen in peritoneal lining cells as shown in B (insert) and G1, G2 (surface epithelium [SE], arrow). As early as the 13th week of gestation, CAIX positive cells were seen in the flat SE of the ovary, the outer muscular layer and rare epithelial cells of the uterus and fallopian tubes (B). Around 26 to 27 weeks, high levels of CAIX expression were transiently seen in the epithelium of fallopian tubes (C1), endometrium (D1), and the cervix (E1). After birth, there was either no CAIX expression (C3) or expression was limited to occasional endometrial cells (D2), reserve cells of the cervix (E2, and corresponding H&E stain in insert, and F1, F2). In the ovary, CAIX expression was observed in SE migrating into the stroma and forming the primordial follicle (PF) (G1, G2). Persistent expression of CAIX was observed in the coelomic remnants: rete testis (H1) and tubule reti (H2). W = gestational age in weeks; D, M = postnatal age in days and months, respectively. Original magnifications: A1, A2, A3, C1, C2, C3, E1, E2 and F2 (20×); B (4×); H1 and H2 (10×); D1, D2, F1, G1 and G2 (40×).