title: Fraction of pluripotent hemopoietic stem cells in DNA synthesis varies with generation age.
abstract: The fraction of pluripotent hemopoietic stem cell (CFU-S) in DNA synthesis (S phase) was evaluated for day 7 through 13-spleen colonies. The CFU-S in S phase in normal bone marrow decreased progressively, from 43% on day 7, to 23% on day 11, and 4% on day 13. The cycling fraction of 5-fluorouracil (5FU)-treated CFU-S was also evaluated. The S phase fraction for CFU-S surviving 5FU was 100.0, 58.8, 54.7, and 25.6% at day 7, 9, 11, and 13, respectively, and the proportion of the fraction also was not constant. The S phase fraction for CFU-S surviving 5FU was much higher than that for normal bone marrow cells; this might be attributed to the extensive regenerating ability of CFU-S surviving 5-FU. The results obtained suggest that a stem cell population in S-phase may exhibit a hierarchy based on the "generation-age hypothesis" (Rosendaal, Hodgson, and Bradley 1979) of the stem cell compartment.
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D002453:Cell Cycle; D002454:Cell Differentiation; D003114:Colony-Forming Units Assay; D004247:DNA / Q000096:biosynthesis; D005720:Gamma Rays; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000528:radiation effects*; D008297:Male; D051379:Mice; D011828:Radiation Chimera; D013154:Spleen / Q000166:cytology*; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors
chemical_list: D004247:DNA; D013936:Thymidine