title: [Ultrastructure and antigens in differentiation of thymus lymphocytes in human embryogenesis].
abstract: Thymus lymphocytes of 7--8-week human embryos have nuclei of irregular form with 1--3 distinct nucleoli characterized by absence of compact chromatin or heterchromatin. The electron-dense cytoplasm of these cells contains polysomes and an insignificant number of mitochondria. No receptors to sheep red blood cells and T antigen are revealed on their surface. In 11--12-week human embryos one can observe a decrease in the size of thymus lymphocytes, appearance of heterochromatin in their nuclei and receptors to sheep red blood cells (79%), and T antigen (60%) on the cell surface. Subsequently the quantity of compact chromatin in thymus lymphoid cells increases, and the cells acquire definitive properties and structure.
mesh_terms: D000954:Antigens, Surface / Q000302:isolation & purification*; D002454:Cell Differentiation; D004622:Embryo, Mammalian / Q000648:ultrastructure*; D005260:Female; D005333:Fetus / Q000648:ultrastructure*; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011971:Receptors, Immunologic / Q000302:isolation & purification*; D013601:T-Lymphocytes / Q000648:ultrastructure*; D013950:Thymus Gland / Q000648:ultrastructure*
chemical_list: D000954:Antigens, Surface; D011971:Receptors, Immunologic
vernacular_title: Ul'trastruktura i antigeny differentsirovki limfotsitov timusa v émbriogeneze cheloveka.