多头绒泡菌核仁染色质的结构

The structure of nucleolar chromatin in Physarum polycephalum.

作者信息

Butler M J, Davies K E, Walker I O

出版信息

Nucleic Acids Res. 1978 Mar;5(3):667-78. doi: 10.1093/nar/5.3.667.

DOI:10.1093/nar/5.3.667

PMID:565509

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC342014/

Abstract

The nucleolar DNA of Physarum polycephalum has been differentially labelled with 3H-thymidine and the structure of the nucleolar chromatin investigated by digestion with micrococcal nuclease. Nucleolar chromatin which had been labelled in G2 phase of the cell cycle and then digested before mitosis had an identical DNA repeat length to main band DNA (165 +/- 5 base pairs) but there was a definite indication that the rate of digestion was faster for nucleolar DNA than for main band DNA. Nucleolar chromatin which had been labelled in G2 and the label chased through mitosis into G2 phase of the next cycle showed an identical DNA repeat length to main band DNA and was also digested at the same rate. We conclude that nucleolar chromatin, at least 25 per cent of which is maximally transcriptionally active in G2, has a nucleosome-like structure.

摘要

用³H-胸腺嘧啶核苷对多头绒泡菌的核仁DNA进行了差异标记，并用微球菌核酸酶消化来研究核仁染色质的结构。在细胞周期的G2期被标记、然后在有丝分裂前进行消化的核仁染色质，其DNA重复长度与主带DNA相同（165±5个碱基对），但有明确迹象表明，核仁DNA的消化速度比主带DNA快。在G2期被标记且标记物经有丝分裂追踪到下一个周期的G2期的核仁染色质，其DNA重复长度与主带DNA相同，消化速度也相同。我们得出结论，核仁染色质至少25%在G2期具有最大转录活性，具有类似核小体的结构。