AN AUTORADIOGRAPHIC INVESTIGATION OF COELOMOCYTE PRODUCTION IN THE PURPLE SEA URCHIN (STRONGYLOCENTROUS PURPURATUS)

Abstract

Brief exposure to tritiated thymidine in vivo or in vitro labels some of the bladder-filiform amebocytes, colorless spherule amebocytes and eleocytes circulating in the perivisceral coelomic fluid of the purple sea urchin; circulating vibratile cells are not labeled. At least a part of coelomocyte production is by division of circulating coelomocytes. Labeled vibratile cells enter the circulation in the weeks following injection of tritiated thymidine. The source of the vibratile cells is probably the parietal peritoneum. The coelomocytes (and most of the other tissues) of young adult sea urchins have the characteristics of expanding, and not renewing, cell populations. Starvation for several months causes a significant reduction in the tritium indices of the bladder-filiform amebocytes, eleocytes and cells of the parietal peritoneum.