About 2% of mouse DNA reassociates at extremely low Cot values (10-7-10-6 mole-liter-1-sec). This DNA fraction was isolated with the aid of nuclease S1 and purified by chromatography on hydroxyapatite. The study of this fraction suggests that it has a structure of hairpin type. The DNA of the hairpins can hybridize with sequences forming the double-stranded regions in pre-mRNA. Probably at least some of the DNA of the hairpins, described as "reversed repeating sequences" of DNA, is transcribed with the formation of structures of hairpin type in pre-mRNA.

中文翻译：

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核前mRNA的结构。VI。动物DNA中的“反向重复”及其与pre-mRNA的双链区杂交。

约2％的小鼠DNA在极低的Cot值（10-7-10-6摩尔升-1秒）下重新结合。借助于核酸酶S1分离该DNA级分，并通过在羟基磷灰石上的色谱法纯化。对这一部分的研究表明，它具有发夹型结构。发夹的DNA可以与在pre-mRNA中形成双链区的序列杂交。发夹的至少某些DNA，被描述为DNA的“反向重复序列”，可能在pre-mRNA中被转录成发夹类型的结构。