The embryonic origin of cells functioning in a peritoneal exudate response of larval Rana pipiens was investigated. Normal larva received injections of sodium caseinate on day 0 and cells in the peritoneal cavity were assayed on days 3, 5, 7, 9, 11, 13 and 16. Experimental animals that received cytogenetically labeled transplants of dorsal mesoderm at 67-72 hours of development were injected with sodium caseinate on day 0 and assayed on days 5, 7 and 9. Feulgen-DNA microdensitometric analysis showed that the peritoneal exudate from days 5, 7, 9 contained hemopoietic cells that were derived from the embryonic transplant. Therefore, dorsal mesoderm gave rise to cells capable of functioning in a peritoneal exudate response to injections of sodium caseinate.
Animals Ascitic Fluid