title: Development of Thy 1 positive mouse thymocytes. Analysis of early fetal thymocytes by flow microfluorometry.
abstract: Early mouse fetal thymocytes were analyzed for cell size and amount of Thy 1 by flow microfluorometry. There were very few Thy 1 positive cells in the embryonic thymus of the 13th day; in the 14th day fetal thymus, the number of Thy 1 positive cells increased, though the Thy 1 content remained at relatively low levels. Both the number of Thy 1 positive cells and the content of Thy 1 greatly increased by the 15th day, but the Thy 1 content was still definitely lower than that of adult thymocytes. These results indicate that Thy 1 negative thymocyte precursors increase in Thy 1 content gradually when they differentiate into thymocytes. The present study also suggests that immature thymocytes like the 15th day fetal thymocytes, even though they are definitely Thy 1 positive, bear Thy 1 at much lower levels than most of the adult thymocytes, indicating a distinct difference in Thy 1 content between immature thymocytes and most of the adult thymocytes.
mesh_terms: D000818:Animals; D000954:Antigens, Surface; D002454:Cell Differentiation; D005333:Fetus / Q000166:cytology / Q000276:immunology*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D005865:Gestational Age; D051379:Mice; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000166:cytology / Q000196:embryology / Q000276:immunology*; D018800:Thy-1 Antigens
chemical_list: D000954:Antigens, Surface; D018800:Thy-1 Antigens