Cockerill P N
Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Victoria, Australia.
Nucleic Acids Res. 1990 May 11;18(9):2643-8. doi: 10.1093/nar/18.9.2643.
The genome is thought to be divided into domains by DNA elements which mediate anchorage of chromosomal DNA to the nuclear matrix or chromosome scaffold. The positions of nuclear matrix anchorage regions (MARs) have been mapped within the 200 kb mouse immunoglobulin heavy chain constant region locus, thereby allowing an estimate of the size of DNA domains within a segment of the genome. MARs were identified in four regions, which appear to divide the locus into looped DNA domains of 30, 20, 30 and greater than 70 kb in length. These DNA domain sizes fall within the range of DNA loop sizes observed in histone-extracted nuclei and chromosomes. In two regions, large clusters of MARs were identified, and many of these MARs lie on DNA fragments that include repetitive DNA elements, perhaps indicating that repetitive DNA integrates into the genome close to MARs, or that some classes of repeats could themselves act as MARs.
基因组被认为是由介导染色体DNA与核基质或染色体支架锚定的DNA元件划分为多个结构域。核基质锚定区域（MARs）的位置已在200 kb的小鼠免疫球蛋白重链恒定区基因座内进行了定位，从而能够估计基因组片段内DNA结构域的大小。在四个区域中鉴定出了MARs，它们似乎将该基因座划分为长度分别为30、20、30和大于70 kb的环状DNA结构域。这些DNA结构域的大小落在从组蛋白提取的细胞核和染色体中观察到的DNA环大小范围内。在两个区域中，鉴定出了大量的MARs簇，其中许多MARs位于包含重复DNA元件的DNA片段上，这可能表明重复DNA在靠近MARs的位置整合到基因组中，或者某些重复序列本身可以充当MARs。
