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

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.

Glycoprotein synthesis in the subcommissural organ of the chick embryo. I. An ontogenetical study using specific antibodies.

Antibodies were raised in rabbit against crude subcommissural organ (SCO) extract of 19 day old chick embryos. After absorption with crude brain extract, the IgG fraction was purified by ion exchange chromatography. The specificity of the antibodies was controlled by immunostaining and by a competition test between lectins (Concanavalin A-Con A- and wheat germ agglutinin-WGA-) and antibodies (A74 IgG).

Detection of sex-specific proteins in chick embryo gonads and mesonephros: effects of estradiol benzoate or tamoxifen on their expression.

Gonadal and mesonephric protein patterns from 19 day old normal chick embryos were investigated by two-dimensional polyacrylamide gel electrophoresis. Under these conditions, several sex-specific polypeptides were detected. As concerns gonadal extracts, four sex-specific polypeptides, all restricted to the cytosol, were present in the testis, whereas three sex-specific polypeptides, two localized in the cytosol, the other being membrane-bound, were identified in the ovary.

[Cytotoxic properties of anti-kidney antibodies in the chick embryo. I--Antibodies reacting with an antigen specific for the proximal segment of the secretory tubules].

The cytotoxic properties of purified antibodies reacting specifically with an antigen of the proximal secretory tubule cells have been studied. Intravenous injections of these antibody preparations together with complement (Guinea pig serum) into 2-3,5 day old or 12-13 day old chick embryos do not interfere with the development of either the meso-or metanephros. Furthermore, when suspensions of live metanephric cells treated first with anti-proximal segment antibodies and second with complement are cultured under organotypic conditions, one observes the reconstitution of all the characteristic segments (proximal, intermediate, distal and collecting) of the urinary tubule.

[Hormonal control of vitellogenin synthesis in the Amphipoda Crustacea Orchestia gammarella (Pallas)].

The presence of a vitellogenin stimulating ovarian hormone (VSOH) in Orchestia gammarella has been demonstrated by gonadectomy and ovary grafting. Vitellogenin synthesis is not affected by molting hormone injection; it decreases after Y-organ (molting gland) cauterization. Studies in progress seem to indicate that the destruction of the median area of the protocerebrum is followed by a decrease of this synthesis.