Nelkin B D, Pardoll D M, Vogelstein B
Nucleic Acids Res. 1980 Dec 11;8(23):5623-33. doi: 10.1093/nar/8.23.5623.
Recent studies indicate that eukaryotic DNA is organized into supercoiled loop domains. These loops appear to be anchored at their bases to an insoluble nuclear skeleton or matrix. Most of the DNA in the loops can be released from the matrix by nuclease digestion; the residual DNA remaining with the nuclear matrix represents sequences at the base of the loops, and possibly other sequences which are intimately associated with the nuclear matrix for other reasons. Using a quantitative application of the Southern blotting technique, we have found this residual DNA from SV40 infected 3T3 cells to be enriched in SV40 sequences, indicating that they reside near matrix-DNA attachment points. An enrichment of 3-7 fold relative to total cellular DNA, was found in each of three different lines of SV40 infected 3T3 cells. Control experiments with globin genes showed no such enrichment in this residual matrix DNA. This sequence specificity suggests that the spatial organization of DNA sequences within loops may be related to the functionality of these sequences within the cell.
最近的研究表明，真核生物的DNA被组织成超螺旋环结构域。这些环似乎在其基部锚定到不溶性的核骨架或核基质上。环中的大部分DNA可通过核酸酶消化从基质中释放出来；残留在核基质中的DNA代表环基部的序列，也可能是由于其他原因与核基质紧密相关的其他序列。通过定量应用Southern印迹技术，我们发现来自SV40感染的3T3细胞的这种残留DNA富含SV40序列，这表明它们位于基质-DNA附着点附近。在三个不同的SV40感染的3T3细胞系中，每个细胞系相对于总细胞DNA都发现有3至7倍的富集。用珠蛋白基因进行的对照实验表明，在这种残留的基质DNA中没有这种富集。这种序列特异性表明，环内DNA序列的空间组织可能与其在细胞内的功能有关。
