蟋蟀中核糖体DNA复合物扩增的三维结构

The three-dimensional organization of the amplified ribosomal DNA complex in Acheta.

作者信息

Lima-de-Faria A

出版信息

Proc Natl Acad Sci U S A. 1974 Dec;71(12):4778-82. doi: 10.1073/pnas.71.12.4778.

DOI:10.1073/pnas.71.12.4778

PMID:4531017

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC433980/

Abstract

The major chromomere of pachytene chromosome 6 in the oocytes of Acheta (Orthoptera) is a region of amplification for ribosomal RNA cistrons (28 S and 18 S). This chromomere was isolated and studied with the scanning electron microscope. It has an outer shell that is smooth at early stages but divides into polygonal plates as indentations appear on its surface. These indentations increase in number as the DNA copies separate from each other and as the ribosomal RNA synthesis progresses. The vertices of the polygonal plates coincide with the positions at which the DNA copies reach the surface of the chromomere during their "puffing" process. The combined information gained from scanning and transmission electron microscopy, DNA measurements, DNA.RNA hybridization, and cytochemistry, leads to a three-dimensional picture of the organization of the amplified ribosomal DNA in its association with ribosomal RNA and protein.

摘要

在蟋蟀（直翅目）卵母细胞中，粗线期染色体6的主要染色粒是核糖体RNA顺反子（28S和18S）的扩增区域。这个染色粒被分离出来并用扫描电子显微镜进行研究。它有一个外壳，在早期阶段是光滑的，但随着其表面出现凹陷，会分裂成多边形板。随着DNA拷贝彼此分离以及核糖体RNA合成的进行，这些凹陷的数量会增加。多边形板的顶点与DNA拷贝在其“胀泡”过程中到达染色粒表面的位置一致。从扫描电子显微镜和透射电子显微镜、DNA测量、DNA - RNA杂交以及细胞化学获得的综合信息，形成了扩增的核糖体DNA与核糖体RNA和蛋白质结合时的三维组织结构图。