Histological characterization of the oviducal structures in guinea fowl (Numida meleagris).

摘要

The structures of the magnum, isthmus and shell gland and the localization of immunoreactive calcium binding protein-D 28 K (CaBP-D 28 K) in the shell gland of 5 guineafowls and 5 fowls were compared histologically. In both species, the mucosal folds in each oviductal segment consisted of the mucosal epithelium and lamina propria containing tubular glands. In the magnum of guineafowls but not fowls, the secondary mucosal folds were well developed forming many large duct-like structures in the lamina propria. There was no significant difference in the structures of mucosal tissues in the isthmus between the 2 species. In the shell gland, the distribution of tubular glands in the lamina propria at the bottom region of mucosal folds was denser than that at the apical region of the fold in guineafowls and fowls. In both species, the tubular gland cells of the shell gland contained dense immunoreactive CaBP-D 28 K. The height of the mucosal folds was significantly greater in the shell gland than in the magnum and isthmus in guineafowls, whereas it was greatest in the magnum in fowls. The height of the mucosal fold in the shell gland was greater in guineafowls than in fowls. It is suggested that structural differences in the oviducal mucosal tissues are responsible for the formation of thicker egg shells in guineafowls compared with fowls.