title: Early genetic events in T cell development analyzed by in situ hybridization.
abstract: In situ hybridization was used to investigate the expression of T cell receptor (TCR) alpha, beta, and gamma mRNAs in developing fetal and adult precursor thymocytes. gamma transcription was observed at the earliest time tested (day 12), followed by beta 12 h later, and TCR alpha on day 16. The early beta transcripts appeared to be from unrearranged or incompletely rearranged (D-J-C) beta loci. V beta region transcription was first detectable on day 14 and transcription of different V beta genes was induced at different times. These results delineate a schedule sequence of TCR gene activation, which begins within 1 d after entry of stem cells into the fetal thymus.
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000235:genetics*; D005333:Fetus / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000032:analysis; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D011995:Recombination, Genetic; D013601:T-Lymphocytes / Q000378:metabolism*; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000276:immunology; D014158:Transcription, Genetic
chemical_list: D000954:Antigens, Surface; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D018800:Thy-1 Antigens