Development of Day-8 Colony-Forming Unit-Spleen Hematopoietic Progenitors During Early Murine Embryogenesis: Spatial and Temporal Mapping

• Published in: Blood Vol. 87; no. 2; pp. 557 - 566
• Main Authors: Medvinsky, Alexander L., Gan, Olga I., Semenova, Maria L., Samoylina, Nina L.
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 15-01-1996; The Americain Society of Hematology
• Subjects: Animals; Aorta - cytology; Aorta - embryology; Bone Marrow Cells; Colony-Forming Units Assay; Digestive System - cytology; Digestive System - embryology; Female; Gestational Age; Gonads - cytology; Gonads - embryology; Hematopoietic Stem Cells - cytology; Hematopoietic System - embryology; Male; Mesonephros - cytology; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Radiation Chimera; Spleen - cytology; Yolk Sac - cytology
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V87.2.557.bloodjournal872557

The ontogeny of the hematopoietic system in mammalian embryos occurs during the yolk sac (YS) and the fetal liver (FL) stages. Events leading to the establishment of hemato-poiesis in the FL remain obscure. The appearance of colony-forming units-spleen (CFU-S) in the FL is preceded by a gradual increase of CFU-S in the YS and a more rapid increase in the AGM region (area comprising dorsal aorta, gonads, and mesonephros) during day 10 of development (Medvinsky et al, Nature 364:64, 1993). By this time, the AGM CFU-S attain a high frequency equivalent to that found in the adult bone marrow. The analogous area gives rise to adult hematopoiesis in amphibians and probably in birds. We present here a more complete picture of CFU-S development during transition from the pre-liver to liver stage of hematopoiesis. (1) Dissectional analysis of the mouse AGM region shows the presence of CFU-S both around the dorsal aorta and in the uro-genital ridges. (2) The embryonic gut also shows low but distinctive CFU-S activity. This initial intra-body pattern of CFU-S distribution in murine embryogenesis parallels that found for primordial germ cells. (3) The beginning of definitive liver hematopoiesis is accompanied by wide dissemination of CFU-S in the embryonic tissues. (4) Comparision of spleen colonies arising from the AGM and YS has shown morphologic differences. In contrast to simple erythroid constitution of the YS colonies, a broader variety of cells are found within the AGM-derived colonies that are similar to those derived from 11-day FL. These data suggest a lineage relationship for hematopoietic progenitors between the AGM region and the FL.