Nishio Y, Shiokawa K, Yamana K
Department of Biology, Faculty of Science, Kyushu University 33 Fukuoka, 812, Japan.
Dev Growth Differ. 1978;20(1):35-40. doi: 10.1111/j.1440-169X.1978.00035.x.
Isolated cells of Xenopus laevis neurulae were labeled with H-uridine at three different temperatures (21°C, 30°C and 10°C), and the pattern of RNA synthesis was examined, using polyacrylamide gels. At 21°C (standard temperature), the synthesis of 28S and 18S ribosomal RNA (rRNA), as well as other RNAs, occurred quite actively. At 30°C (higher temperature), the syntheses of rRNA, 4S and heterogeneous RNA were all increased about twofold (Q = 2). When the temperature was lowered to 10°C, however, the accumulation of both 28S and 18S rRNA was inhibited nearly completely, while the other RNAs were still synthesized at a 50% level. The absence of 40S rRNA precursor at 10°C makes it highly likely that at the lowered temperature the transcription of rRNA precursor is inhibited. These effects of temperature changes on RNA synthesis were all reversible: the synthesis returned to a normal rate within 4 hr in those cells that had previously been exposed to the lower or higher temperature for 6 hr.
用³H-尿苷在三种不同温度（21°C、30°C和10°C）下对非洲爪蟾神经胚的分离细胞进行标记，并使用聚丙烯酰胺凝胶检测RNA合成模式。在21°C（标准温度）时，28S和18S核糖体RNA（rRNA）以及其他RNA的合成相当活跃。在30°C（较高温度）时，rRNA、4S和不均一RNA的合成均增加了约两倍（Q = 2）。然而，当温度降至10°C时，28S和18S rRNA的积累几乎完全受到抑制，而其他RNA仍以50%的水平合成。10°C时缺乏40S rRNA前体使得在较低温度下rRNA前体的转录很可能受到抑制。温度变化对RNA合成的这些影响都是可逆的：在先前暴露于较低或较高温度6小时的细胞中，合成在4小时内恢复到正常速率。
