SPECIFIC DISINTEGRATION OF NEMATOCYSTS INHYDRA JAPONICABY TREATMENT WITH PROPARGYLGLYCINE

When Hydra japonica was treated with 2 mM D,L-c-propargylglycine, a specific inhibitor of γ-cystathionase, for 75 h, the number of desmonemes present in the tentacles dropped drastically. H. isorhiza and A. isorhiza numbers also showed smaller drops, but the stenotele number remained unchanged. Total cell numbers and cell composition except for the battery cells and nematocytes, remained unchanged. The disappearance of the mature desmonemes was apparently due to their specific disintegration in the living hydra, and not to inhibition of differentiation from interstitial cells to nematocytes, and/or their migration, nor accelerated nematocyst discharge from the battery cells. Hydra lacking desmonemes may be useful in investigating how the proportions of each nematocyte type are kept constant, and how nematocyte differentiation is regulated.