T cell progenitors emerge earlier than B cell progenitors in the murine fetal liver.
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.
Kawamoto
H
H
Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Japan.
Ikawa
T
T
Ohmura
K
K
Fujimoto
S
S
Katsura
Y
Y
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*
D000945:Antigens, Differentiation, T-Lymphocyte; D020395:Receptors, Interleukin-7; D019009:Proto-Oncogene Proteins c-kit; D017493:Leukocyte Common Antigens