The Role of Specific Surface Antigens in Cell Adhesion. Part Ii. Studies on Embryonic Amphibian Cells

Abstract

Holtfreter (1943) first demonstrated that embryonic amphibian cells could be disaggregated by exposure to his standard solution (Holtfreter, 1931) at high pH.Townes (unpubl.) has utilized this technique to investigate the problem of cell affinities. The following account is based on these previous investigations.If an amphibian gastrula or neurula is exposed to Holtfreter's solution at a pH greater than 9.6, the pigmented surface coat becomes soft and is partially dissolved."Within a few minutes cracks appear in it ; new disruptions follow, until the whole surface is broken up into small dark islets, surrounded by much larger white interfaces. A closer examination reveals that each islet is the centre of a group of cells, attached to it in a radial orientation" (Holtfreter, 1943; p. 292).Under the action of the alkali, the surface coat, which is disrupted at the cell boundaries, retracts in the form of a black cap to the pole of each cell. This cap progressively decreases in size as pigment streams to the interior of the cell.Within 20 minutes, the entire gastrula or neurula is a heap of dissociated spherical cells which can be separated from one another with a glass needle. If the solution is now removed and replaced with 2-3 changes of Holtfreter's solution at pH 7.8, the entire process is reversed.

The origins of the molecular era of adhesion research

“…Tyler and Weiss proposed that the adhesion between cells arises from an antibody–antigen-like interaction between cell surface molecules 12,13 . Consistent with this, Spiegel showed that antibodies against the surfaces of both sponges and amphibian embryos inhibited the reaggregation of dissociated cells in a cell type- and species-dependent manner, respectively 14,15 . On the basis of studies in the 1940s of neural regeneration, Sperry proposed the chemoaffinity (also known as chemospecificity) hypothesis 16,17 .…”

Involvement of blood-group-B-active trisaccharides in Ca 2+ -dependent cell-cell adhesion in the Xenopus blastula

“…Involvement of blood-group-B-active trisaccharides in Ca 2+ -dependent cellcell adhesion in the Xenopus blastula Spiegel (1954) used a blocking antibody to study cellcell adhesion in the anuran Rana pipiens as early as 1954. Studies on the cell-cell adhesion mechanisms of the African clawed frog (Xenopus laevis) began later.…”

The Reaggregation of Dissociated Sponge Cells

“…Thus Tyler (1945) cites mainly the selective reaggregation of experimentally dissociated sponge cells and the segregative movements in experimental combinations of embryonic amphibian tissues (Holtfreter, 1939). Recently (Spiegel, 1951a(Spiegel, , 1954b, we have been able to demonstrate the presence of specific surface antigens in these tissues.…”