Characterization of multiple erythroid progenitors available in large quantity from rabbit marrow

We have examined the characteristics of erythroid progenitors from rabbit marrow and assessed the potential of this species as a source from which substantial quantities of erythroid progenitors could be obtained. Plasma clot cultures of rabbit marrow demonstrate colonies consistent with erythroid colony forming units (CFUE) by day 2 and colonies resulting from two types of burst forming units (BFUE) seen on days 3 and 8-9, respectively. Characteristic colony morphologies were noted from each cell type as well as differential sensitivity to erythropoietin (Ep) with discrete maximum responses for each progenitor. Distinct buoyant density characteristics were noted when the precursors were subjected to isopyknic separation on linear density gradients of polyvinylpyrrolidone-coated silica. The total nucleated marrow cells obtained from each animal ranged from 1.7-4.7 X 10(9). The average yields for each progenitor wee 1.71(+/-0.43) X 10(7) for CFUE, 1.99(+/-0.36) X 10(6) for 3 day BFUE and 1.24(+/-0.11) X 10(6) for 8-9 day BFUE.