Figure 3

Oviduct-specific gene expression and immunohistochemical analysis from juvenile (10-week-old) and egg-laying adult (30-week-old) oviducts. A) The competitive RT-PCR of egg-white-specific genes including OVA, AVD, OVM, and LYZ, and hormone receptor-derived genes including ESR1 and PGR were analyzed. PCR products were also loaded on agarose gels with ethidium bromide. The competitive RT-PCR analysis (*P < 0.05) showed that the expression levels of oviduct-specific genes in the adult oviduct were significantly higher than those in the juvenile oviduct. However, the relative expression levels of ESR1 and PGR in the juvenile oviduct were significantly higher than in the adult oviduct (*P < 0.05). B) Oviductal magnum sections from the juvenile and the adult were immunostained with anti-OVA, anti-ESR1, and anti-PGR antibodies. In the juvenile oviduct (a-c), rarely stained anti-OVA result (a) was observed compared with the immunoreactivities of anti-ESR1 (b) and anti-PGR antibody (c), which strongly stained the epithelium (arrows). In the adult oviduct (d-i), anti-OVA antibodies mainly bound to the tubular gland (Tg; d, g). Anti-ESR1 antibody bound to the oviductal epithelium and toward the outer layer (Ol) of tubular gland compared with the inner layer (Il) of tubular gland (e, h). The anti-PGR antibody was positive to the tubular gland and epithelium (f, i). E, luminal surface of the oviductal epithelium; Il, inner layer of the tubular gland; Ol, outer layer of the tubular gland; S, stroma; Tg, tubular gland. Bars = 100 μm (d-f), 50 μm (g-i), and 25 μm (a-c).