A Study of the Immunohistochemical Localization of the Progesterone and Oestrogen Receptors in the Magnum of the Immature Ostrich, Struthio camelus

Abstract

The immunolocalization of the progesterone (PR) and oestrogen receptors (OR), in the magnum of the immature ostrich, was investigated during periods of ovarian activity and inactivity. In the immature ostrich, with an active ovary, numerous well-developed tubular glands were present in the lamina propria. Significantly, PR immunostaining was strong in the surface epithelium and tubular glands of these birds. In contrast, weak staining for the PR was observed in the surface epithelium of birds with inactive ovaries. Tubular gland formation, in these birds, was indicated by bud-like invaginations of the surface epithelium. Oestrogen receptor immunoreactivity was negligible in both birds with active and inactive ovaries. These findings suggest that steroid hormones, produced by the active ovary of the immature ostrich, influence the differentiation of the magnum. Furthermore, the action of these steroid hormones appears to be mediated through the PR.

Immunolocalization of Intermediate Filaments and Laminin in the Oviduct of the Immature and Mature Japanese Quail (Coturnix coturnix japonica)

“…Tubular glands in immature quails were sparsely distributed, while glands in mature birds were compacted. Similar observations have been made in the oviductal regions of the immature and mature domestic fowl (Breen and De Bruyn, 1969;Palmiter and Wrenn, 1971), Japanese quail (Hoffer, 1971;Eroschenko, 1979;Pageaux et al, 1986;Berg et al, 2001), ostrich (Madekurozwa, 2002(Madekurozwa, , 2004 and rhea (Parizzi et al, 2008). A study by Yu and Marquardt (1973) has shown that the egg white protein ovalbumin is secreted by magnal tubular glands.…”

A Morphological and Immunohistochemical Study of Healthy and Atretic Follicles in the Ovary of the Sexually Immature Ostrich (Struthio camelus)

“…Although the occurrence of atresia in the avian has been well documented, no information is available on atresia in the ostrich. Of particular interest, in the present study, was atresia in the ovary of the sexually immature ostrich, which has been shown to exhibit ovarian and oviducal differentiation during periods of long daylength (Madekurozwa, 2002a,b,2004).…”

Morphological Features of the Luminal Surface of the Magnum in the Sexually Immature Ostrich (Struthio camelus)

“…The structure and function of the magnum has been documented in a variety of birds, such as the domestic fowl (Bakst and Howarth, 1975; Bakst, 1978; Davidson, 1986), the Japanese quail (Eroschenko and Wilson, 1974), the guinea fowl (Ogwuegbu et al., 1989; Ogwuegbu and Aire, 1990) and the pied myna (Gupta and Maiti, 1987). In addition, information is available on the maturation of the magnum in the quail (Pageaux et al., 1986), the domestic fowl (Yu and Marquardt, 1973) and the ostrich (Madekurozwa, 2002a). The maturation of the magnum in the ostrich has received particular attention in an effort to gain more knowledge on the reproductive biology of the female ostrich.…”

“…The maturation of the magnum in the ostrich has received particular attention in an effort to gain more knowledge on the reproductive biology of the female ostrich. It is intriguing that seasonal morphological changes occur in the magnum of the immature ostrich (Madekurozwa, 2002a). The study by Madekurozwa (2002a) highlighted the light microscopic and immunohistochemical differences between birds with active and inactive ovaries, collected at different times of the year.…”

“…It is intriguing that seasonal morphological changes occur in the magnum of the immature ostrich (Madekurozwa, 2002a). The study by Madekurozwa (2002a) highlighted the light microscopic and immunohistochemical differences between birds with active and inactive ovaries, collected at different times of the year. Interestingly, this appears to be the first report indicating morphological changes in the magnum of sexually immature ostriches sampled at different times of the year.…”