Glycoprotein synthesis in the subcommissural organ of the chick embryo II. an immunochemical study

Abstract

In the chick embryo, A74 immunoaffinity chromatography allowed to purify specific glycoproteins relevant to the SCO ventricular secretory process. The eluted fractions of the subcommissural organ (SCO), the cerebral hemispheres (CH) and the medulla oblongata (MO) were compared using the Concanavalin A (Con A) and wheat germ agglutinin (WGA) staining procedures after western-blotting. Analysis of the optical density of the reactive bands allowed to estimate the relative concentration of the various glycopeptides in the eluted fractions. In the SCO-eluted fractions at least ten Con A-positive glycopeptides were identified, their apparent molecular weight ranging from 240 to 42 kD. Only three of these appeared to be WGA-positive (98, 88, and 52 kD). In the CH-eluted fractions only a 52 kD Con A- and WGA-positive glycopeptide was revealed, while in the MO-eluted fractions a 32 kD glycopeptide was also Con A- and WGA-positive. These results are discussed in regard to the known biosynthesis pathway of complex type glycoproteins.

Continuous delivery of a monoclonal antibody against Reissner’s fiber into CSF reveals CSF-soluble material immunorelated to the subcommissural organ in early chick embryos

“…A parallel situation may occur in the chick embryo. As described previously, immunocytochemical and lectin studies of chick embryo SCO have suggested that the ependymal cells start to secrete into the ventricle at E7 (Schoebitz et al 1986;Karoumi et al 1990). Such a conclusion is based on the presence of AFRU-positive fibrilar aggregates on top of the SCO apical surface.…”

“…RF grows caudally by the addition of SCO-glycoproteins at its cephalic end and extends along the brain aqueduct, the fourth ventricle and the central canal of the spinal cord (Sargent 1900;Sterba et al 1967;Leonhardt 1980; E.M. Rodriguez et al 1992). The SCO develops early during ontogeny (Oksche 1956;Naumann 1986;Schoebitz et al 1986;Naumann et al 1987) and the embryonic development of the SCO-RF complex has been studied in rat (Castaneyra-Perdomo et al 1983;Bouchaud 1983, 1986;Naumann et al 1987), rabbit (Kimble and Mollgard 1975), chicken (Wingstrand 1953;Schoebitz et al 1986;Naumann et al 1987;Karoumi et al 1990;R. Meiniel et al 1993;Didier et al 1995;Cifuentes et al 1996) and humans (Oksche 1956;Wislocki and Roth 1958;Oksche 1961;Olsson 1961;Mollgard 1972; E.M. .…”

Identification of a high molecular weight polypeptide in the subcommissural organ of the chick embryo

“…3) of our extracts may be in an amount too low to be detected by AFRU in immunoblot. Karoumi et al (1990b) have performed immunoaffinity chromatography of chick embryo SCO extracts using a specific antiserum. In blots of the eluted fractions, they found several bands of molecular weight lower than 250 kDa that were stained by lectins and thus considered to represent secretory glycoproteins.…”

Reissner’s fiber formation depends on developmentally regulated factors extrinsic to the subcommissural organ

“…The embryonic development of the SCO-RF complex has been studied in rat (Castaneyra-Perdomo et al 1983;Bouchaud 1983, 1986;Naumann et al 1987), rabbit (Kimble and Mollgard 1975), chicken (Wingstrand 1953;Schoebitz et al 1986;Naumann et al 1987;Karoumi et al 1990;Meiniel et al 1993) and humans (Oksche 1956;Wislocki and Roth 1958;Oksche 1961;Olsson 1961;Møllgard 1972;Rodriguez et al 2001). By using antibodies raised against bovine RF (Rodriguez et al 1984) and recognizing chick SCO secretion, Schoebitz et al (1986Schoebitz et al ( , 1993 have performed a detailed immunocytochemical study of chick SCO development.…”