GALL J G
J Biophys Biochem Cytol. 1959 Mar 25;5(2):295-308. doi: 10.1083/jcb.5.2.295.
The ribbon-like macronucleus of Euplotes eurystomus pinches in half amitotically at each cell division. Several hours before the actual division two lightly staining duplication bands (reorganization bands) appear at the ends of the nucleus and approach each other slowly, finally meeting near the middle. Distal to the bands, that is, in regions through which the bands have already passed, the concentration of DNA (Feulgen) and "histone" (alkaline fast green) is greater than in the central zone. These facts suggest the hypothesis that DNA-histone synthesis takes place in a sequential fashion starting at the tips of the nucleus and proceeding to the middle. That this hypothesis is correct is shown by autoradiographic and photometric observations. Tritium-labelled thymidine is incorporated only in a limited region immediately distal to the bands. The average amount of Feulgen dye bound by the nucleus rises as the duplication bands approach each other, and is double the presynthesis value by the time the bands meet. A similar rise in the alkaline fast green dye is seen in duplicating nuclei, although no completely post-synthesis values were obtained in this study. The quantitative data are consistent with the assumption that the macronucleus contains a number of DNA-histone "units," presumably chromosomes, each of which duplicates once and only once.
阔口游仆虫的带状大核在每次细胞分裂时进行无丝分裂，缢裂为两半。在实际分裂前数小时，两条浅染的复制带（重组带）出现在细胞核两端，并缓慢相互靠近，最终在细胞核中部附近会合。在复制带远端，即复制带已经经过的区域，DNA（福尔根染色法）和“组蛋白”（碱性固绿染色法）的浓度高于细胞核中央区域。这些事实提示了这样一个假说：DNA - 组蛋白的合成以一种顺序方式进行，从细胞核的两端开始，向中间推进。放射自显影和光度测定观察结果表明这个假说是正确的。氚标记的胸腺嘧啶核苷仅掺入到复制带紧邻的有限区域。随着复制带相互靠近，细胞核结合的福尔根染料平均量增加，当复制带会合时，该量是合成前值的两倍。在正在复制的细胞核中也观察到碱性固绿染料有类似的增加，尽管在本研究中未获得完全合成后的数值。定量数据与以下假设一致：大核含有许多DNA - 组蛋白“单位”，推测为染色体，每个单位仅复制一次。
