ULTRACYTOCHEMICAL STUDY ON THE BEHAVIOR OF THE NURSE CELL GIANT GRANULES IN THE SEA URCHIN OVARY

抄録

Acid phosphatase (ACPase) activity in the sea urchin ovary, Hemicentrotus pulcherrimus, was investigated by ultracytochemistry. There were significant differences in the ACPase active structures according to the morphological changes of the ovarian cycles of the sea urchin ovary. ACPase active structures appeared mainly in the cytoplasm of the nurse cells, whereas in other cells in the ovary almost none.
In the nurse cells reaction products were located in 1) spherical granules, about 1-3μm in diameter, which consists of fine granules, 2) some kinds of giant granules and 3) irregularly shaped dense bodies. The reaction products also appeared in a small number of tubules, but not in Golgi apparatus nor nucleus. In the oocytes reaction products were appeared very weakly in the yolk granules during and immediately after the breeding season.
It is considered that the above three types of ACPase reactive structures are equivalent to 1) primary lysosome, 2) secondary lysosome which corresponds to the digesting relict ova that were phagocytized by nurse cells after the breeding season and 3) residual body. The morphogenesis and behavior of the giant granules are discussed.