Jelinek W R
Proc Natl Acad Sci U S A. 1978 Jun;75(6):2679-83. doi: 10.1073/pnas.75.6.2679.
Fragments from the DNA of Chinese hamster ovary cells produced by restriction endonuclease EcoRI were cloned in Charon 16A lambda bacteriophage and examined for the ability to hybridize in situ with 32P-labeled double-stranded regions from heterogeneous nuclear RNA (hnRNA). Of 235 clones tested, 87 (37%) contained sequences that hybridized with the double-stranded hnRNA. Nine of these were examined for the presence of inverted repeat DNA structures (ir-DNA) by electron microscopy. All nine contained at least two elements of ir-DNA. Analysis of heteroduplexes formed from the DNAs of the different clones as well as T1 fingerprint analysis of the double-stranded hnRNA hybridized to each of the nine clones suggest that there is detectable nucleotide sequence homology in the various ir-DNAs. There are ca 3 X 10(5) ir-DNA pairs in the haploid Chinese hamster ovary cell genome.
用限制性内切酶EcoRI切割中国仓鼠卵巢细胞的DNA所产生的片段，被克隆到Charon 16A λ噬菌体中，并检测其与来自不均一核RNA（hnRNA）的32P标记双链区域进行原位杂交的能力。在测试的235个克隆中，有87个（37%）含有能与双链hnRNA杂交的序列。通过电子显微镜对其中9个进行了反向重复DNA结构（ir-DNA）的检测。所有9个都至少含有两个ir-DNA元件。对由不同克隆的DNA形成的异源双链体的分析，以及对与这9个克隆各自杂交的双链hnRNA的T1指纹分析表明，在各种ir-DNA中存在可检测到的核苷酸序列同源性。在单倍体中国仓鼠卵巢细胞基因组中约有3×10⁵个ir-DNA对。
