title: T cell progenitors emerge earlier than B cell progenitors in the murine fetal liver.
abstract: The developmental potential of individual cells in the Lin-c-kit+CD45+IL-7R+ (IL-7R+) population from murine fetal liver was investigated using a clonal assay capable of determining the potential of a progenitor to give rise to myeloid, T, and B cells. Unipotent progenitors generating T cells (p-T) or B cells (p-B) but not other types of progenitors were found in the IL-7R+ population. A large proportion of progenitors at day 12 of gestation are p-T, whereas the frequency of p-T dramatically decreases with gestational age. In marked contrast, p-B are very rare by day 12, but they rapidly increase thereafter. These findings strongly suggest that the commitment of multipotent progenitors to T and B cell lineages occurs independently.
authors.affiliation: Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kawamoto
authors.forename: T
authors.initials: T
authors.lastname: Ikawa
authors.forename: K
authors.initials: K
authors.lastname: Ohmura
authors.forename: S
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Katsura
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001402:B-Lymphocytes / Q000166:cytology*; D019070:Cell Lineage; D003114:Colony-Forming Units Assay; D005314:Embryonic and Fetal Development; D005865:Gestational Age; D006411:Hematopoiesis, Extramedullary; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D017493:Leukocyte Common Antigens / Q000032:analysis; D008099:Liver / Q000166:cytology / Q000196:embryology* / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D020395:Receptors, Interleukin-7 / Q000032:analysis; D013601:T-Lymphocytes / Q000166:cytology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D020395:Receptors, Interleukin-7; D019009:Proto-Oncogene Proteins c-kit; D017493:Leukocyte Common Antigens