Dimitrov S I, Tateossyan H N, Russanova V R, Karagyozov L, Pashev I G
Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia.
Eur J Biochem. 1992 Mar 15;204(3):977-81. doi: 10.1111/j.1432-1033.1992.tb16719.x.
The association of ribosomal RNA genes with histones as a function of their expression has been studied in Xenopus laevis erythrocytes, where the genes are silent, and tadpoles at stage 40, where these genes are actively transcribed. Isolated nuclei were either treated with formaldehyde or irradiated with an ultraviolet laser to cross-link proteins to DNA. The covalently linked protein-DNA complexes were purified by centrifugation through CsCl and immunoprecipitated with antibodies against H1, H2A and H4. DNA from the precipitated complexes was analysed for the presence of ribosomal DNA sequences by hybridization to specific probes. The actively transcribed ribosomal genes from X. laevis embryos are associated with H1, H2A and H4 as are the non-transcribed genes in the erythrocytes.
核糖体RNA基因与组蛋白的关联作为其表达的一种功能，已在非洲爪蟾红细胞（其中这些基因处于沉默状态）以及第40阶段的蝌蚪（其中这些基因被积极转录）中进行了研究。分离出的细胞核要么用甲醛处理，要么用紫外激光照射，以使蛋白质与DNA交联。通过氯化铯离心纯化共价连接的蛋白质-DNA复合物，并用抗H1、H2A和H4的抗体进行免疫沉淀。通过与特异性探针杂交，分析沉淀复合物中的DNA是否存在核糖体DNA序列。非洲爪蟾胚胎中被积极转录的核糖体基因与红细胞中的非转录基因一样，都与H1、H2A和H4相关联。
