Flickinger R A
Cell Differ. 1982 Apr;11(2):63-9. doi: 10.1016/0045-6039(82)90020-3.
The use of an inhibitor (0.4 N (NH4)2SO4) and an activator (sodium polydextran sulfate) of initiation of transcription in nuclei of frog embryos in vitro indicated that initiation sites for transcription are relatively A--T-rich. Comparison of incorporation of labeled ATP, UTP, and GTP, when initiation of transcription is prevented, indicates that initiation sites become relatively less A--T-rich as development proceeds. Inhibition of initiation of transcription in isolated nuclei blocks the normal increase in rate of transcription that occurs when cells enter the S phase, showing that an increased level of transcription depends upon a greater number of initiation sites.
在体外对蛙胚细胞核中转录起始的抑制剂（0.4N硫酸铵）和激活剂（聚葡聚糖硫酸钠）的使用表明，转录起始位点相对富含A-T。当转录起始被阻止时，对标记的ATP、UTP和GTP掺入情况的比较表明，随着发育的进行，起始位点相对富含A-T的程度降低。在分离的细胞核中转录起始的抑制会阻断细胞进入S期时正常发生的转录速率增加，这表明转录水平的提高取决于更多的起始位点。
