Shinomiya T, Ina S
Mitsubishi Kasei Institute of Life Sciences, Tokyo, Japan.
Nucleic Acids Res. 1991 Jul 25;19(14):3935-41. doi: 10.1093/nar/19.14.3935.
Chromosomal DNA replication units in early embryos of D.melanogaster were studied using two-dimensional gel replicon mapping techniques. DNA was prepared from nuclei encapsulated into agarose beads. This method substantially improved preservation of replication intermediates more than standard DNA preparation methods, and allowed us to detect replication intermediates for even single-copy chromosomal regions without their selective enrichment. Analysis with tandem repeats of histone genes indicated that DNA replication initiates at multiple locations on the repeating unit. The initiation sites were not localized to a defined site, but rather distributed throughout the repeating unit. DNA replication on a single-copy chromosomal region was also suggested to initiate at numerous sites, probably with little regard for the specific DNA sequences.
利用二维凝胶复制子图谱技术研究了黑腹果蝇早期胚胎中的染色体DNA复制单元。从包裹在琼脂糖珠中的细胞核中制备DNA。与标准DNA制备方法相比，这种方法显著改善了复制中间体的保存，并使我们能够检测到单拷贝染色体区域的复制中间体，而无需对其进行选择性富集。对组蛋白基因串联重复序列的分析表明，DNA复制在重复单元的多个位置起始。起始位点并不局限于一个特定的位点，而是分布在整个重复单元中。单拷贝染色体区域的DNA复制也可能在许多位点起始，可能与特定的DNA序列关系不大。
