title: Defective transient endogenous spleen colony formation in S1/S1d mice.
abstract: WCB6F1 mice of the genotype S1/S1d did not form transient 5-day endogenous spleen colonies following midlethal irradiation, either spontaneously or in response to postirradiation bleeding. Their hematologically normal (+/+) littermates produced colonies equivalent in number and morphologic type to a normal strain (D2B6F1), as evaluated by both macroscopic and microscopic criteria. Bone marrow cells from S1/S1d mice, when transplanted into lethally irradiated +/+ mice, were able to generate equivalent numbers of transient endogenous spleen colonies (TE-CFUs), as compared to that obtained when syngeneic +/+ marrow cells were injected into lethally irradiated +/+ recipients. A defective growth of an early class of hematopoietic progenitor cells, resulting in the clinical course of the S1/S1d anemia is suggested and confirms previous reports on the microenvironmental nature of this abnormality.
mesh_terms: D000740:Anemia / Q000235:genetics* / Q000503:physiopathology; D000818:Animals; D016026:Bone Marrow Transplantation; D002452:Cell Count; D002454:Cell Differentiation; D002999:Clone Cells / Q000166:cytology; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains / Q000235:genetics*; D013154:Spleen / Q000166:cytology / Q000528:radiation effects; D013997:Time Factors