title: Distribution of terminal deoxynucleotidyl transferase in bovine serum albumin gradient-fractionated thymocytes and bone marrow cells of normal and leukemic mice.
abstract: The distribution of terminal deoxynucleotidyl transferase (TdT) peaks I and II, in single cell suspensions of thymuses, bone marrow, and peripheral lymphoid organs fractionated in discontinuous bovine serum albumin gradients, was examined in a variety of mouse strains and Fischer 344 rats to relate the normal patterns of thymocyte differentiation to the leukemic process. TdT peaks I and II were found in fractions A (10 to 23%), B (23 to 26%), and C (26 to 29%) of the thymus of both normal and leukemic C57BL/6 mice, whereas only peak I was found in the same fractions of AKR mice. TdT in bone marrow was found mainly in fraction A in both normal and leukemic mice. The specific activity of TdT in this fraction, which comprises only 1 to 5% of the total bone marrow cell population, was similar to that of the thymus. The cell population of fraction A of the bone marrow was found to increase (10 to 15-fold) in leukemic mice. Only low levels of TdT activity were found in either whole or fractionated bone marrow of athymic NIH Swiss (nu/nu) mice.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000201:enzymology*; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D007942:Leukemia, Experimental / Q000201:enzymology* / Q000209:etiology; D007953:Leukemia, Radiation-Induced / Q000201:enzymology / Q000209:etiology; D051379:Mice; D008815:Mice, Inbred Strains; D008819:Mice, Nude; D051381:Rats; D011916:Rats, Inbred F344; D013601:T-Lymphocytes / Q000201:enzymology*; D013950:Thymus Gland / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D004254:DNA Nucleotidyltransferases