EDSTROEM J E, GALL J G
J Cell Biol. 1963 Nov;19(2):279-84. doi: 10.1083/jcb.19.2.279.
The base composition of RNA's extracted from chromosomes, nucleoli, nuclear sap, and cytoplasm of Triturus oocytes has been determined by microelectrophoresis. The chromosomal RNA has a content of guanine+cytosine equal to that of DNA, but there is no complementarity in the composition as for DNA. Nuclear sap contains a highly variable RNA with a tendency towards high uracil values. Nucleolar and cytoplasmic RNA's are similar in composition and both are of the guanine-cytosine rich type. The chromosomes and nucleoli contain roughly equivalent amounts of RNA, somewhat less than is present in the nuclear sap. The RNA/DNA ratio of the whole chromosomes is about 10. However, the ratio in the synthetically active regions, the loops, is much higher, since the loops contain all the chromosomal RNA but only a small fraction of the DNA.
通过微电泳法测定了蝾螈卵母细胞染色体、核仁、核液和细胞质中提取的RNA的碱基组成。染色体RNA中鸟嘌呤+胞嘧啶的含量与DNA相等,但在组成上不像DNA那样具有互补性。核液含有高度可变的RNA,尿嘧啶值往往较高。核仁RNA和细胞质RNA在组成上相似,且均为富含鸟嘌呤-胞嘧啶的类型。染色体和核仁中RNA的含量大致相当,略少于核液中的含量。整个染色体的RNA/DNA比值约为10。然而,在合成活跃区域(环)中的比值要高得多,因为环中包含了所有的染色体RNA,但只含有一小部分DNA。