Secretory cells in the optic tentacles of the snails, Helix aspersa and H. pomatia, have been investigated for the cytoplasmic localization of certain enzymes. The collar cells, considered to be neurosecretory, and the lateral oval cells, were those examined. Acid phosphatase activity is found in the cytoplasm of both cells, in scattered spheroids called the β-bodies. This enzymatic activity indicates that the β-bodies may be lysosomes, as does their ultrastructural appearance. In the 2 cell types, the activity of both alkaline phosphatase and thiamine pyrophosphatase is localized in crescentic bodies considered to correspond to the Golgi lamellae, and in some of the β-bodies. The latter enzyme also exists in the cortices of the α-bodies which, like the β-bodies, are lipid-containing globules. The activity of both cytochrome oxidase and succinate dehydrogenase is found, not only in granules, rods, and filaments interpreted as the mitochondria, but also on the cortices of some or all of the β-bodies. It is concluded that in invertebrates, the lipochondria may be the sites of activity of many different enzymes which in vertebrates are restricted to distinct cell organelles.
Dkk1 inhibits malignant transformation induced by Bmi1 via the β‐catenin signaling axis in WB‐F344 oval cells
