Harris M
J Natl Cancer Inst. 1980 Jun;64(6):1495-501. doi: 10.1093/jnci/64.6.1495.
Sublines with increased survival at elevated temperatures were obtained by repeated exposure of V79 Chinese hamster lung cells to 44.5 degrees C followed by regrowth of survivors to mass populations at 37 degrees C. After three cycles, the time at 44.5 degrees C required to reduce cell survival to 37% (D0 value) increased from 4.6 to 26.3 minutes. Clonal isolates retained their resistance to thermal stress for at least 3 months in culture at 37 degrees C and showed distinctive differences from precursor cells in growth rate and colonial morphology. These differences disappeared in hybrids constructed between resistant and sensitive cells. In assays of 44.5 degrees C, hybrid survival was only slightly increased over levels obtained with sensitive cells. Heat resistance and associated marker characteristics thus appear to be recessive or weakly codominant. Cytohybrids were also constructed by fusing cytoplasts from sensitive cells to nucleated heat-resistant cells. No cytoplasmic transfer of marker characteristics was detected in these combinations, which suggests that controls for heat resistance are nuclear in origin.
通过将V79中国仓鼠肺细胞反复暴露于44.5摄氏度，然后让存活细胞在37摄氏度下生长至大量群体，获得了在高温下存活率增加的亚系。经过三个循环后，将细胞存活率降低至37%（D0值）所需的在44.5摄氏度下的时间从4.6分钟增加到了26.3分钟。克隆分离株在37摄氏度的培养中至少3个月保持对热应激的抗性，并且在生长速率和集落形态上与前体细胞表现出明显差异。这些差异在抗性细胞和敏感细胞之间构建的杂种中消失了。在44.5摄氏度的测定中，杂种的存活率仅比敏感细胞获得的水平略有增加。因此，耐热性和相关的标记特征似乎是隐性的或弱共显性的。通过将敏感细胞的细胞质体与有核耐热细胞融合也构建了细胞杂种。在这些组合中未检测到标记特征的细胞质转移，这表明耐热性的控制起源于细胞核。
