Aglianó A M, Nacci A, Reymond C, Appleby D, Spohr G
Eur J Biochem. 1979 Mar 15;95(1):203-13. doi: 10.1111/j.1432-1033.1979.tb12955.x.
The globin mRNA sequences present in duck erythroblast nuclei appear under non-denaturing conditions to be associated with heterogeneous nuclear RNA (hnRNA) molecules of various sizes. Under denaturing conditions, however, the bulk of the globin mRNA sequences associated with hnRNA are released as molecules of size close to that of the active globin mRNA. To find out whether hydrogen-bonded structures occur in situ or arise after RNA extraction, nuclei were treated with aminomethyltrioxalen and exposed to ultraviolet light. This treatment generates covalent links between opposite strands of double-stranded nuclei acids, which were visualised by electron microscopy. It appears that, after cross-linking, a fraction of the globin mRNA sequences present in nuclei is associated with high-molecular-weight hnRNA molecules by a link found associated with a band of 0.9 x 10(6) molecular weight approximately. It is suggested that within the erythroblast nucleus, globin mRNA sequences are associated by hydrogen bonds with RNA of high molecular weight. These structures may represent intermediate steps in globin mRNA processing.
在非变性条件下，鸭成红细胞核中存在的珠蛋白mRNA序列似乎与各种大小的不均一核RNA（hnRNA）分子相关联。然而，在变性条件下，与hnRNA相关联的大部分珠蛋白mRNA序列会以大小接近活性珠蛋白mRNA的分子形式释放出来。为了弄清楚氢键结构是在原位形成还是在RNA提取后产生，用氨甲基三氧杂蒽处理细胞核并使其暴露于紫外线下。这种处理会在双链核酸的互补链之间产生共价连接，通过电子显微镜可以观察到。似乎在交联后，细胞核中存在的一部分珠蛋白mRNA序列通过一种与大约0.9×10⁶分子量的条带相关联的连接与高分子量hnRNA分子相连。有人提出，在成红细胞核内，珠蛋白mRNA序列通过氢键与高分子量RNA相关联。这些结构可能代表珠蛋白mRNA加工过程中的中间步骤。
