Raina J L, Metzer E, Ravin A W
Mol Gen Genet. 1979 Mar 5;170(3):249-59. doi: 10.1007/BF00267058.
Donor DNA in its initially bound, single-stranded form exists in a chromosomally-unassociated complex where it is resistant to exogenous DNase I but sensitive to micrococcal nuclease. Most of the complexes are readily recuperable from the supernatant of recipients converted into spheroplasts. Subsequent to formation of this superficially located complex, donor DNA progressively associates with the recipient chromosome into which it is eventually integrated. Treatment of recipients with ethidium bromide at various times after initial DNA binding almost immediately halts translocation of whatever donor material is not yet synapsed with the chromosome. On the other hand, donor DNA that has already synapsed experiences no difficulty in becoming genetically integrated. Some degradation occurs to DNA that fails to undergo translocation as a result of ethidium bromide treatment, the acid-soluble products appearing in the culture medium. DNA in untranslocated complexes surviving treatment is not appreciably different in single-strand length from that in untreated complexes. When these surviving complexes are isolated from a cell lysate, the contained DNA can be shown by spectrofluorometry to have bound the drug.
供体DNA最初以单链形式存在于一种与染色体不相关的复合物中，在此状态下它对外源DNA酶I有抗性，但对微球菌核酸酶敏感。大多数复合物很容易从转化为原生质球的受体上清液中回收。在形成这种位于表面的复合物之后，供体DNA逐渐与受体染色体结合，并最终整合到其中。在最初的DNA结合后的不同时间用溴化乙锭处理受体，几乎会立即阻止任何尚未与染色体联会的供体物质的易位。另一方面，已经联会的供体DNA在进行基因整合时没有困难。由于溴化乙锭处理而未能发生易位的DNA会发生一些降解，酸溶性产物出现在培养基中。经处理后存活的未易位复合物中的DNA单链长度与未处理复合物中的DNA没有明显差异。当从细胞裂解物中分离出这些存活的复合物时，通过荧光光谱法可以显示其中所含的DNA与该药物结合。
