Perkins H D, Bedo D G, Howells A J
Division of Biochemistry and Molecular Biology, School of Life Sciences, Australian National University, Canberra.
Chromosoma. 1992 Mar;101(5-6):358-64. doi: 10.1007/BF00346015.
In the course of making a Lucilia cuprina genomic DNA library, a ladder of bands was seen in partial Sau3A digests. Complete digestion reduced this ladder to predominantly monomer units of approximately 190 bp. Nine independently isolated copies of this repeat were cloned and sequenced. Only two of these isolates are identical in sequence, the most divergent being 71% homologous. This satellite DNA occurs in all three wild-type strains tested, and, for the single case examined, in the embryonic, larval, pupal, and adult DNA. It represents approximately 3%-4% of the genome. Data obtained from in situ chromosome hybridizations indicate that this sequence is concentrated around the centromeric regions of the autosomes and over most of the sex chromosomes. Labelling is much stronger in mitotic compared with polytene chromosomes showing directly that this centromeric satellite DNA is grossly under-replicated during polytenization. This under-replication is even more pronounced on the sex chromosomes compared with the autosomes.
在构建铜绿蝇基因组DNA文库的过程中，部分Sau3A酶切产物中出现了条带阶梯现象。完全酶切后，该阶梯主要变为约190 bp的单体单元。对该重复序列的9个独立分离拷贝进行了克隆和测序。这些分离物中只有两个序列相同，差异最大的同源性为71%。这种卫星DNA存在于所有测试的三种野生型菌株中，并且在所检查的单个样本中，存在于胚胎、幼虫、蛹和成虫的DNA中。它约占基因组的3%-4%。原位染色体杂交获得的数据表明，该序列集中在常染色体的着丝粒区域以及大部分性染色体上。与多线染色体相比，有丝分裂染色体上的标记要强得多，这直接表明这种着丝粒卫星DNA在多线化过程中严重复制不足。与常染色体相比，性染色体上的这种复制不足更为明显。
