title: Erythroid progenitor cells and stimulating factors during murine embryonic and fetal development.
abstract: Murine embryonic and fetal yolk-sacs, peripheral blood, and livers were assayed for hemopoietic multipotential and progenitor cell content between days 6 and 13 of gestation. Multipotential cells (Mix-CFC), erythroid-committed progenitor cells (BFU-E), and nonerythroid progenitor cells (predominantly GM-CFC) were assayed by their ability to form hemopoietic colonies in vitro when stimulated by pokeweed-mitogen-stimulated spleen-cell-conditioned media (as a source of Multi-CSF) and either human or murine erythropoietin. Late erythroid progenitor cells (CFU-E) were stimulated to form colonies by erythropoietin. Mix-CFC, BFU-E, and nonerythroid cells were first detected on day 8 in yolk-sacs, day 9 in peripheral blood, and day 11 in liver. Maximum absolute numbers of yolk-sac Mix-CFC (182), BFU-E (331), and non-erythroid CFC (1358) occurred at 11 days of gestation. The maximum frequency of peripheral blood mix-CFC (24/10(5) cells) and BFU-E (55/10(5) cells) occurred at ten days of gestation. The absolute numbers of hepatic Mix-CFC, BFU-E, nonerythroid CFC, and CFU-E increased exponentially from 11 to 13 days' gestation. CFU-E were first detected at nine days in peripheral blood, at ten days in yolk-sac, and 11 days in liver and at all ages were equally responsive to erythropoietin. The maximum frequency (151/10(5) cells) of CFU-E in the peripheral blood and the maximum number per yolk-sac (1699) both occurred on day 11 of gestation. In confirmation of previous studies, yolk-sac fluid was found to contain a macrophage colony-stimulating activity. In addition, an activity capable of stimulating fetal liver CFU-E was also detected in yolk-sac fluid. However, no activity (Multi-CSF) capable of stimulating Mix-CFC or BFU-E was detected in either yolk-sac fluid or fetal plasma.
mesh_terms: D000818:Animals; D003114:Colony-Forming Units Assay; D003115:Colony-Stimulating Factors / Q000032:analysis / Q000502:physiology*; D004622:Embryo, Mammalian / Q000166:cytology*; D005314:Embryonic and Fetal Development; D004912:Erythrocytes / Q000378:metabolism / Q000502:physiology*; D004920:Erythropoiesis; D004921:Erythropoietin / Q000502:physiology; D005260:Female; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000502:physiology*; D008099:Liver / Q000196:embryology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D011247:Pregnancy; D015017:Yolk Sac / Q000032:analysis / Q000166:cytology
chemical_list: D003115:Colony-Stimulating Factors; D004921:Erythropoietin