Journal of Cell Science, Vol 2, 563-572, Copyright © 1967 by Company of Biologists

Submitted on February 14, 1967
Revised on June 12, 1967

Coated Vesicles in Absorptive Cells of Hydra

¹ Anatomy Department, University of Wisconsin, Madison, Wisconsin, U.S.A.

The apical cytoplasm of absorptive cells in hydra gastroderm contains numerous vesicles having a discoidal shape, an asymmetrical membrane and a peculiar coat firmly attached to the luminal surface of the membrane. The coat of these ‘discoidal coated vesicles’ consists of a highly ordered array of subunits made up of ‘pegs’ and globules. That these vesicles are involved in selective absorption and transport of materials from the gastrovascular cavity can be seen readily using ferritin as tracer. They are also involved in the uptake of particulate glycogen and the phagocytosis and possibly the subsequent digestion of complex food droplets. It may reasonably be supposed that the array of the coat subunits indicates a similar array of the molecular constituents of the membrane to which it is attached. In tangential sections of the membrane a compressed hexagonal lattice is seen which could fit the coat array.