Ishiwata K, Oikawa A
Nucleic Acids Symp Ser. 1981(10):149-52.
Nuclei of human lymphoblastoid cells NL3 incorporated dUMP into DNA in vitro. The rate and extent of this incorporation were less than those of dTMP, presumably due to the presence of dUTPase and uracil-DNA glycosylase in nuclear preparations. NL3 cell extracts released only about a half of the misincorporated uracil as free base from nuclei, their chromatin and chromatin reconstituted from dUMP-containing DNA and calf thymus chromosomal protein, though almost all uracil from reconstituted chromatin containing PBS1 phage DNA. The cell extracts also release 10-40% of 3-methyladenine from methylated nucleosome monomers and dimers, and chromatins reconstituted from methylated DNA and poly (dA . dT). The shorter molecule lost fewer 3-methyladenine.
人淋巴母细胞系NL3的细胞核在体外可将脱氧尿苷一磷酸（dUMP）掺入DNA。这种掺入的速率和程度低于胸腺嘧啶脱氧核苷酸（dTMP），推测是由于核制剂中存在脱氧尿苷三磷酸酶（dUTPase）和尿嘧啶-DNA糖基化酶。NL3细胞提取物仅从细胞核、其染色质以及由含dUMP的DNA和小牛胸腺染色体蛋白重构的染色质中释放出约一半错误掺入的尿嘧啶作为游离碱，尽管几乎所有来自含PBS1噬菌体DNA的重构染色质中的尿嘧啶都被释放。细胞提取物还从甲基化核小体单体和二聚体以及由甲基化DNA和聚（dA·dT）重构的染色质中释放出10%-40%的3-甲基腺嘌呤。较短的分子损失的3-甲基腺嘌呤较少。
