Erickson J M, Rushford C L, Dorney D J, Wilson G N, Schmickel R D
Gene. 1981 Dec;16(1-3):1-9. doi: 10.1016/0378-1119(81)90055-x.
Eco-RI-A fragments of the human ribosomal RNA gene family from two types of tissue and three individuals were cloned in lambda vectors and compared by restriction enzyme digestion and electron microscopy. The EcoRI fragment A contains (i) 0.2 kb of the 3' end of the 18S rDNA, (ii) 2.5 kb of internal transcribed spacer and the 5.8S rDNA, and (iii) 4.6 kb of the 28S rDNA gene. All of the six cloned rDNA fragments isolated are identical by these analyses. Moreover, all contain a HincII site that is absent in about 50% of the rDNA identified by genomic blotting. Polymorphism in the nontranscribed spacer rDNA was studied in genomic blots of BamHI-digested DNA, using the 3' end of the 28S rDNA as a probe. The boundaries between the 18S rDNA, internal transcribed spacer, 28s rDNA, and external nontranscribed spacer were determined by R-loop analysis, further defining the organization of the ribosomal RNA precursor.
从两种组织和三个个体中获取的人类核糖体RNA基因家族的Eco-RI-A片段被克隆到λ载体中，并通过限制性内切酶消化和电子显微镜进行比较。EcoRI片段A包含：（i）18S rDNA 3'端的0.2 kb，（ii）2.5 kb的内部转录间隔区和5.8S rDNA，以及（iii）28S rDNA基因的4.6 kb。通过这些分析，分离出的六个克隆rDNA片段均相同。此外，所有片段都含有一个HincII位点，而在通过基因组印迹鉴定的约50%的rDNA中不存在该位点。使用28S rDNA的3'端作为探针，在BamHI消化的DNA的基因组印迹中研究了非转录间隔区rDNA的多态性。通过R环分析确定了18S rDNA、内部转录间隔区、28S rDNA和外部非转录间隔区之间的边界，进一步明确了核糖体RNA前体的组织形式。
