title: T cells and the thymus in developing zebrafish.
abstract: The expression of genes encoding T cell receptor (TCR) alpha was used to follow the development of the thymus and to analyze the distribution of T cells in zebrafish. In the thymus, expression was first detected, by in situ hybridization, at four days post fertilization. In RNA extracted from whole fish, TCRalpha transcripts were also detected at four days and reached adult levels at three weeks. At six weeks, TCRalpha was expressed throughout the thymus, whereas rag1 expression was localized to the peripheral regions. Expression of TCRalpha outside the thymus was detected at nine days. In adult peripheral organs, the greatest expression was in the pronephros, mesonephros and intestine; expression in the spleen became greater as fish age. Three new, relatively highly expressed, TCR Valpha families were identified.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Nadia
authors.initials: N
authors.lastname: Danilova
authors.forename: Valerie S
authors.initials: VS
authors.lastname: Hohman
authors.forename: Frank
authors.initials: F
authors.lastname: Sacher
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ota
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Willett
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Steiner
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004625:Embryo, Nonmammalian / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D018398:Homeodomain Proteins / Q000378:metabolism; D017403:In Situ Hybridization; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000196:embryology; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013154:Spleen / Q000196:embryology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism*; D013950:Thymus Gland / Q000196:embryology / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism*
chemical_list: D018398:Homeodomain Proteins; D011948:Receptors, Antigen, T-Cell; C064658:RAG-1 protein