Abstract: Histone and DNA bind together to form the nucleosome, but this tight binding can loose at some times to facilitate other proteins to interact with DNA. The authors constructed histone H2A-pEGFP and fibrillarin-pDsRed1 expression vectors, and studied the dynamics of H2A,using fluoresence recovery after photobleaching (FRAP) techniques. It was showed that in a small number of interphase cells cultured in vitro, H2A not only distributed in the nucleoplasm, but also congregated in the nucleolar area. The FRAP analysis indicated that H2A in the nucleolar area moved remarkably faster than that in the nucleoplasm. It suppose that nucleolus may be as a pool of histone H2A at some special time during cell cycle.

Key words: histone, nucleolus, FRAP

摘要： 在真核细胞中，核小体的核心结构组蛋白被DNA紧密缠绕，但是这种紧密的结合有时也可能变得松散，以利于其他蛋白与DNA的结合。将组蛋白H2A与绿色荧光蛋白的融合表达载体和核仁纤维蛋白(fibrillarin)与红色荧光蛋白的融合表达载体共转染COS7细胞，利用荧光漂白恢复(FRAP)技术研究了H2A在细胞核内的动态变化。结果显示，在少数间期细胞的核仁区有组蛋白聚集现象，且此区域内H2A的运动速度显著地高于非核仁区的H2A，推测该现象仅出现于细胞周期的某个时期。

关键词: 组蛋白, 核仁, 荧光漂白恢复