LONG-TERM MYELOPOIETIC CULTURES FROM THE RENAL HEMATOPOIETIC-TISSUE OF THE RAINBOW-TROUT, ONCORHYNCHUS-MYKISS W - PHENOTYPIC CHARACTERIZATION OF THE STROMAL CELLS

This study describes the conditions for the long-term culture of the r enal hematopoietic tissue of the rainbow trout, Oncorhynchus mykiss, t he characterization of the stromal cells, and their relationships with myelopoietic cells. The long-term cultures consisted of stromal cells , which supported active myelopoiesis. Stromal cells were analyzed by enzyme-cytochemical techniques and electron microscopy. Major stromal cell types in long-term cultures consisted of fibroblastic reticular c ells and epithelioid cells. Myelopoietic cells differentiated in close association with the fibroblastic reticular cells, and mature granulo cytes were released into the culture medium.