The bHLH gene Hes1 is essential for expansion of early T cell precursors.
Mice mutant for the bHLH gene Hes1, which is known to keep cells in a proliferative state, mostly lack thymus. Transfer of Hes1-null fetal liver cells into RAG2-null host mice normally reconstitutes B cells but fails to generate mature T cells in the thymus. In the reconstituted thymus, T cell differentiation is arrested at the CD4(-)CD8(-) double negative (DN) stage. Both the initial T cell receptor (TCR)-independent and the subsequent TCR-dependent selective expansion during the DN stage are severely affected. Thus, Hes1 is essential for the earliest thymocyte expansion in a cell-autonomous manner.
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D004268:DNA-Binding Proteins / Q000235:genetics; D015329:Gene Rearrangement, T-Lymphocyte; D018257:Helix-Loop-Helix Motifs / Q000235:genetics*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology; D018398:Homeodomain Proteins / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D000072056:Transcription Factor HES-1