DEVELOPMENT OF MACRONUCLEAR ANLAGE IN CILIATE CHILODONELLA-UNCINATA .1. MORPHOLOGICAL AND CYTOPHOTOMETRIC STUDIES ON EVOLUTION OF DNA
DEVELOPMENT OF MACRONUCLEAR ANLAGE IN CILIATE CHILODONELLA-UNCINATA .1. MORPHOLOGICAL AND CYTOPHOTOMETRIC STUDIES ON EVOLUTION OF DNA
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DOI：
10.1007/bf00326506
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发表时间：
1974-01-01
期刊：
影响因子：
1.6
通讯作者：
SCHNEIDE.S
中科院分区：
文献类型：
--
作者：
PYNE, CK;RUCH, F;SCHNEIDE.S
C. uncinata 中大核原基的发育分三个步骤。在第一阶段，在原基中可以看到明显的福尔根阳性元素。随着原基体积的增加，后者的DNA含量从2℃增加到约32℃，表明有四个复制周期。同时，Feulgen 阳性元件的数量也增加，表明这些体代表单个染色体，并且在每个复制周期后，子染色体会分裂。在第二阶段，原基体积大大增加，并显示出扩散的福尔根染色，其中没有可辨别的结构元素。第三阶段，小Feulgen阳性颗粒重新出现在原基内，并逐渐变大、数量增多；与此同时，原基作为一个整体开始凝结，并且变得越来越浓密，直到它出现即将分裂的营养大核。在第二阶段和第三阶段，大核原基的DNA含量不断增加，直到接近营养大核的G2值，约为128℃。但在第一阶段和第二阶段之间是否存在一些DNA消除的问题尚未解决，需要进一步研究。
The development of the macronuclear anlage in C. uncinata occurs in three steps. During stage I, distinct Feulgen-positive elements are visible in the anlage. Along with the increase in the volume of the anlage, the DNA content of the latter increases from 2 C to about 32 C, indicating four cycles of replication. Simultaneously, the number of Feulgen-positive elements also increases, suggesting that these bodies represent the individual chromosomes and that after each duplication cycle, the daughter chromosomes fall apart. During stage II, the anlage increases greatly in volume and shows a diffused Feulgen stain, in which no structured elements are discernible. During stage III, small Feulgen-positive granules reappear inside the anlage, and gradually become bigger as well as more numerous; at the same time the anlage as a whole starts condensing and becomes more and more densely staining, until it attains the appearance of a vegetative macronucleus about to divide. During stages II and III, the DNA content of the macronuclear anlage goes on increasing, until it nearly reaches the G2value of the vegetative macronucleus, which is about 128 C. The problem as to whether there is an elimination of some DNA in between stages I and II has however not yet been resolved and needs further study.