Bendig M M, Hentschel C C
Nucleic Acids Res. 1983 Apr 25;11(8):2337-46. doi: 10.1093/nar/11.8.2337.
HeLa cells were transfected with recombinant DNAs containing the embryonic histone gene repeat of P.miliaris (h22) inserted in either orientation into a pBR-SV40 vector. After 2 to 3 days cytoplasmic RNA was analyzed for authentic sea urchin histone gene transcripts. The correct 5' termini of all five histone genes were detected, three (H2B, H2A and H3) at relatively high levels. In contrast, termination was largely aberrant with the correct 3' terminus of only the H2B mRNA found in significant amounts. The levels of histone gene transcription were dependent on the presence, but not the orientation, of SV40 DNA in the recombinant plasmid. The efficiency of initiation of transcription of the individual sea urchin histone genes in HeLa cells was very similar to that previously observed in Xenopus oocytes. The termination pattern, however, was quite different in that oocytes, all but the H3 gene terminate efficiently. The idiosyncrasies in termination efficiencies for these two heterologous transcription systems may reflect the presence of termination factors which are relatively species or even tissue specific and only some of which recognize the sea urchin "terminators" correctly.
将含有插入到pBR - SV40载体中的粟酒裂殖酵母胚胎组蛋白基因重复序列（h22）的重组DNA以任一方向转染HeLa细胞。2至3天后，分析细胞质RNA中的真实海胆组蛋白基因转录本。检测到所有五个组蛋白基因的正确5'末端，其中三个（H2B、H2A和H3）的水平相对较高。相比之下，终止大多异常，仅在大量存在的H2B mRNA中发现了正确的3'末端。组蛋白基因转录水平取决于重组质粒中SV40 DNA的存在，但不取决于其方向。HeLa细胞中单个海胆组蛋白基因的转录起始效率与先前在非洲爪蟾卵母细胞中观察到的非常相似。然而，终止模式却大不相同，在卵母细胞中，除了H3基因外，所有基因都能有效终止。这两个异源转录系统在终止效率上的特性可能反映了终止因子的存在，这些终止因子相对具有物种甚至组织特异性，并且只有其中一些能正确识别海胆“终止子”。
