De Winter R F, Moss T
Nucleic Acids Res. 1986 Aug 11;14(15):6041-51. doi: 10.1093/nar/14.15.6041.
S1 mapping of Xenopus laevis ribosomal RNA transcripts, both in oocyte microinjection experiments and in vivo, shows that all but 212 bp of the so-called "non-transcribed" spacer (NTS) of the ribosomal DNA repeat is transcribed as part of the primary ribosomal transcript. The 40S pre-ribosomal RNA (pre-rRNA) is therefore a processing intermediate. The primary ribosomal transcript co-terminates with the previously described spacer transcripts [Moss], at a site 213 bp upstream of the 40S pre-rRNA initiation site. This mode of transcription suggests a simple mechanism for the recently proposed phenomenon of "readthrough-enhancement", [Moss et al, Moss], where readthrough transcription from an upstream gene may enhance transcription of a gene immediately downstream in the tandem ribosomal repeat.
非洲爪蟾核糖体RNA转录本的S1图谱显示，无论是在卵母细胞显微注射实验还是在体内实验中，核糖体DNA重复序列中所谓的“非转录”间隔区（NTS）除212 bp外，其余部分都作为初级核糖体转录本的一部分进行转录。因此，40S前核糖体RNA（pre-rRNA）是一种加工中间体。初级核糖体转录本与先前描述的间隔区转录本[莫斯]共终止于40S pre-rRNA起始位点上游213 bp处的一个位点。这种转录模式为最近提出的“通读增强”现象[莫斯等人，莫斯]提供了一种简单的机制，即上游基因的通读转录可能增强串联核糖体重复序列中紧邻下游基因的转录。
