Krolewski J J, Schindler C W, Rush M G
J Mol Biol. 1984 Mar 25;174(1):41-54. doi: 10.1016/0022-2836(84)90364-4.
Small polydisperse circular DNA (spcDNA) isolated from the BSC-1 line of African Green monkey kidney cells was digested with the restriction endonuclease BamHI and cloned in bacteriophage lambda. The resulting library of 25,000 phage was then screened for the presence of the Alu family of short interspersed nucleotide sequences, and four of the 100 Alu-positive clones were characterized. In summary: (1) all four clones contained regions other than Alu that were homologous to the BSC-1 chromosome. Two contained Alu plus unique chromosomal DNA, one contained Alu plus an uncharacterized repetitive chromosomal DNA, and one contained Alu plus both unique and a specific tandemly repeated chromosomal DNA (alpha-satellite); (2) all four clones were derived from extrachromosomal circular DNAs and not from the accidental cloning of a very small amount of contaminating chromosomal material assumed to be present in spcDNA preparations; and (3) one clone represented an intact circular DNA with a restriction endonuclease cleavage map that was a circularly permuted version of its chromosomal homologue.
从非洲绿猴肾细胞的BSC - 1系中分离出的小多分散环状DNA（spcDNA）用限制性内切酶BamHI消化，并克隆到噬菌体λ中。然后对所得的25,000个噬菌体文库进行筛选，以寻找短散在核苷酸序列的Alu家族，对100个Alu阳性克隆中的4个进行了表征。总结如下：（1）所有4个克隆都含有除Alu以外的与BSC - 1染色体同源的区域。两个含有Alu加上独特的染色体DNA，一个含有Alu加上未表征的重复染色体DNA，一个含有Alu加上独特的和特定的串联重复染色体DNA（α卫星）；（2）所有4个克隆都来自染色体外环状DNA，而不是来自假定存在于spcDNA制剂中的极少量污染染色体物质的偶然克隆；（3）一个克隆代表一个完整的环状DNA，其限制性内切酶切割图谱是其染色体同源物的环状排列版本。
