The mesoglea of Hydra. IV. A qualitative radioautographic study of the protein component

The synthesis of the collagen-elastin-like protein of the mesoglea of Hydra pseudoligactis was studied using tritiated proline. Radioproline was incorporated by direct incubation in “hot” hydra culture medium and by feeding Hydra labeled Artemia nauplii. Hydra cells are permeable to proline in the culture medium and exhibit radioproline incorporation within two hours in regenerating animals. Non-regenerating Hydra exhibit incorporation only after a longer time. Isolated mesoglea of Hydra also exhibits incorporation of radioproline subsequent to its appearance in the cells. Epithelio-muscular cells and digestive cells appear to be responsible for mesoglea synthesis. The distribution of radioproline label in Hydra mesoglea can be explained on the basis of the theory of directed cell movement previously presented by the authors and the observed synthesis of mesoglea protein.