Thiol Groups and Morphogensis

Abstract

WE have recently shown^1,2 that β-mercaptoethanol (a strongly reducing –SH-containing substance) markedly inhibits morphogenetic movements (gastrulation, closure of neural plate) in amphibian eggs. The oxidized counterpart of β-mercaptoethanol (dithiodiglycol) produces a thickening of the neural plate; the same type of abnormalities can be obtained with other thiol reagents, iodoacetamide and chloropicrine for example³. Another interesting action of β-mercaptoethanol is the complete inhibition of cap formation in anucleate fragments of the alga Acetabularia, without appreciable effect on the growth in length of the stalks⁴. It is a surprising fact that β-mercaptoethanol exerts strongly inhibitory effects on morphogenesis in biological systems so different as amphibian eggs and Acetabularia; the purpose of this communication is to summarize the results obtained in further experiments made on Acetabularia, amphibian eggs and regenerating animals (axolotl tadpoles, planarians).