Innervation of the ovarian interstitial cell of the chick embryo.

Electron microscopic examination of the developing ovary of 15-20-day chick embryos revealed that the interstital cells well innervated. Nerve fibres and nerve endings were observed in close contact with steroid-producing cells.     

Alteration of cell shape in the early chick embryo mesoderm by neuraminidase

Summary Living chick embryo mesoderm cells (stages 3 to 5) were exposed to neuraminidase. The mesoderm cells changed shape losing their long thin processes and become like primitive streak cells, with short flat processes. Ruthenium red staining of such treated embryos shows that the surface coat on the mesoderm cells is reduced in thickness. These results show that cell shape in the chick embryo mesoderm is at least partly determined by the thickness and the composition of the surface coat.Acknowledgment. It is a pleasure to thank Professor F. Beck for the facilities of the Department of Anatomy, University of Leicester, and Mr. G. L. C. McTurk of the University of Leicester Scanning Electron Microscope Unit for operating the ISI 60 SEM. Mr Jeff Smith and Mrs Doris Duncan gave us valuable technical assistance and Dr. A. J. Rowe kindly allowed us to use the facilities of the Electron Microscope Unit, University of Leicester School of Biological Sciences, in specimen preparation.     

Acetylcholine receptors in the gastrulating chick embryo

Summary Muscarinic acetylcholine receptors are present in the gastrulating chick embryo.     

Extended survival of the chick embryo in vitro

Résumé On décrit une technique pour obtenir la survie prolongée des embryons du poulet in vitro, et son emploie pour cultiver des tissus isolés du système nerveux centrale.     

Relationship between regeneration of cell surface glycoproteins in trypsin-treated chick embryo fibroblasts and cell adhesion to the substratum

Summary The ability of cells to adhere to a substratum was altered by treatment with trypsin but was restored after a 1.5-h culture. A concomitant incorporation of [³H] leucine and [⁴C] glucosamine in the trypsin-sensitive cell surface glycoproteins was observed and almost reached a plateau within 1.50 h following the treatment with trypsin.     

Relationship between regeneration of cell surface glycoproteins in trypsin-treated chick embryo fibroblasts and cell adhesion to the substratum

The ability of cells to adhere to a substratum was altered by treatment with trypsin but was restored after a 1.5-h culture. A concomitant incorporation of [3H] leucine and [14C] glucosamine in the trypsin-sensitive cell surface glycoproteins was observed and almost reached a plateau within 1.50 h following the treatment with trypsin.     

Cell division and cell death during regression of the chick embryo Müllerian ducts.

In 9-day-old chick embryos, decreased DNA synthesis and enhanced necrosis were observed in a defined area of the right female Müllerian ducts, supporting the idea of the existence of a regression process in this organ. In the male ducts, decreased DNA synthesis and a low level of necrosis were present all over the studied portion of the organ.     

On the regulative capacity of the chick embryo limb bud

Zusammenfassung Wenn bei Ablation von 90% des Materials der Flügelanlage von Hühnerembryonen der Stadien 18–20 eine dünne Marginalschicht des Mesenchyms und des deckenden Ektodermsin situ bleibt, erhält man in einem bedeutsamen Prozentsatz der Fälle eine vollständige Regulierung.