期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：2
页码：734-738
DOI：10.1073/pnas.74.2.734
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The cellular and subcellular distribution of terminal deoxynucleotidyl transferase (DNA nucleotidylexotransferase; nucleosidetriphosphate:DNA deoxynucleotidylexotransferase, EC 2.7.7.31 ) in thymocytes and peripheral lymphocytes from rat, mouse, and calf was studied by immunofluorescence using rabbit antiserum to homogeneous transferase from calf. Terminal transferase was readily detected in approximately 75% of cortical thymocytes, but not in medullary thymocytes or lymph node lymphocytes. The enzyme appeared to be present predominantly in the cytoplasm of positive thymocytes in ethanol-fixed cell smears and frozen sections. The reactivity of anti-terminal-transferase for thymocytes could be neutralized with purified calf enzyme. Results of experiments in which thymocytes were separated on 7-step discontinuous Ficoll density gradients suggested that cortical thymocytes are heterogeneous with respect to terminal deoxynucleotidyl transferase content.
