title: Mechanisms of adhesion among cells of the early chick blastoderm. Role of calcium ions in the adhesion of extraembryonic endoderm cells.
abstract: Cells from the extraembryonic endoderm of the gastrulating chick embryo adhere to one another in the absence of divalent cations. The addition of Mg2+ions to the medium has no effect on the aggregation kinetics but the addition of Ca2+ions increases the number of cells which aggregate and also stabilizes adhesion. Some aggregation also occurs when cells are suspended in saline devoid of Ca2+and Mg2+ions and supplemented with EGTA, a Ca2+ion complexing agent, but adhesion is not stabilized. Shear sensitive and shear resistant bonds form in Ca-containing as well as in EGTA-containing saline. These results suggest that extraembryonic endoderm cells have Ca2+indepedent and Ca2+dependent mechanisms of adhesion.
authors.affiliation: Department of Zoology, Univesity of Alberta, T6G 2E9, Edmonton, Alberta, Canada.
authors.forename: Nadine
authors.initials: N
authors.lastname: Milos
authors.affiliation: Department of Zoology, Univesity of Alberta, T6G 2E9, Edmonton, Alberta, Canada.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Zalik
keywords: Chick; Divalent cations; Embryonic cell adhesion