Lykkesfeldt A E, Andersen H A
J Cell Sci. 1977 Jun;25:95-102. doi: 10.1242/jcs.25.1.95.
On a chemically defined growth medium the degree of substitution of thymidine with 5-bromodeoxyuridine (BUdR) in DNA of Tetrahymena pyriformis was controlled by the concentration of tetrahydrofiolic acid, BUdR and thymidine in the medium. A correlation between the degree of BUdR substitution in DNA and the reduction in rate of total RNA synthesis has been established. It was found that the reduction of total RNA synthesis results from inhibition of transcription of all RNA species which have been measured. However, independent of the degree of BUdR substitution in DNA, a preferential inhibition of the synthesis of 25s and 17s ribosomal RNA was found. It is concluded that the various genes may respond differently to BUdR substitution with respect to transcription.
在化学限定的生长培养基上，梨形四膜虫DNA中胸腺嘧啶核苷被5-溴脱氧尿嘧啶核苷（BUdR）取代的程度受培养基中四氢叶酸、BUdR和胸腺嘧啶核苷浓度的控制。已确定DNA中BUdR取代程度与总RNA合成速率降低之间存在相关性。结果发现，总RNA合成的减少是由于所测定的所有RNA种类的转录受到抑制。然而，无论DNA中BUdR取代程度如何，均发现25s和17s核糖体RNA的合成受到优先抑制。得出的结论是，各种基因在转录方面对BUdR取代的反应可能不同。
