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Human marrow erythropoiesis in culture: II. Heterogeneity in the morphology, time course of colony formation, and sedimentation velocities of the colony‐forming cells
Author(s) -
Ogawa Makio,
Maceachern Martha D.,
Avila Lobelia
Publication year - 1977
Publication title -
american journal of hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.456
H-Index - 105
eISSN - 1096-8652
pISSN - 0361-8609
DOI - 10.1002/ajh.2830030104
Subject(s) - erythropoiesis , colony forming unit , colony morphology , bone marrow , biology , human bone , morphology (biology) , haematopoiesis , andrology , immunology , microbiology and biotechnology , medicine , zoology , anemia , stem cell , biochemistry , genetics , in vitro , bacteria
Time course examination on human marrow erythxoid colony formation was carried out in methylcellulose culture by scoring colonies with clear signs of hemoglobinization. The colonies were arbitrarily divided into 3 categories: small colony, containing fewer than 50 cells; medium‐sized colony, containing 50‐500 cells; and large colony, containing more than 500 cells. The majority of the large colonies assumed the morphology of bursts consisting of several subcolonies. Small colonies became hemoglobinized, reached their peak on Day 4, and rapidly disappeared. Medium‐sized colonies gradually increased, reached their peak on Day 8, and then slowly declined. Large colonies became hemoglobinized beginning on Day 11 and continued to be present until Day 18. We then examined the cell sizes of the erythropoietic precursor using sedimentation velocity analysis. Bone marrow nucleated cells were separated in a Staput apparatus and fractions of equal volume were analyzed for their content of colony‐forming units (CFU). The mean of modal sedimentation velocities of late erythroid precursors, CFU‐E 4 (CFU‐E for 4‐day‐old small colonies), was 6.46 mm/hour, while that of CFU‐E 14 (CFU‐E for 14‐day‐old large colonies) was 5.17 mm/hour. These studies demonstrate the heterogeneity of human erythroid precursors assayable in culture and emphasize the necessity for clear standardization of scoring colonies.