Comings D E
J Cell Biol. 1966 Mar;28(3):437-41. doi: 10.1083/jcb.28.3.437.
To obtain an estimate of the rate of RNA synthesis by the heterochromatic sex chromatin body, human female fibroblasts were labeled with uridine-5-H(3) and radioautographed. The number of grains over the sex chromatin body was compared with the number of grains over a comparable area of euchromatin. The ratio was 0.37. When corrected for the higher content of DNA per unit area in heterochromatin, the maximum rate of RNA synthesis by the DNA of the sex chromatin body was approximately 18% of the rate of RNA synthesis by a comparable amount of euchromatin DNA. The rate of RNA synthesis by the sex chromatin body did not increase significantly with partial despiralization of this chromatin at prophase.
为了估计异染色质性染色质体的RNA合成速率，用尿苷-5-H(3)标记人类女性成纤维细胞并进行放射自显影。将性染色质体上的银粒数量与常染色质可比区域上的银粒数量进行比较。该比例为0.37。校正异染色质中每单位面积较高的DNA含量后，性染色质体DNA的最大RNA合成速率约为等量常染色质DNA的RNA合成速率的18%。在前期，随着该染色质部分解旋，性染色质体的RNA合成速率没有显著增加。
