Rommerskirch W, Graeber I, Grässmann M, Grässmann A
Institut für Molekularbiologie und Biochemie, Freie Universität Berlin, FRG.
Nucleic Acids Res. 1988 Feb 11;16(3):941-52. doi: 10.1093/nar/16.3.941.
Homologous recombination between microinjected SV40 DNA fragments and endogenous SV40 DNA in COS7 cells was analysed by immunofluorescence staining and DNA blotting. Time course experiments revealed that recombination between the transferred (trans) DNA and the chromosomal DNA occurred about 8 hours after microinjection with high efficiency in a gene dose independent fashion. Deletions of up to 1018 basepairs (bp) within the early or the late SV40 region were efficiently repaired after the transfer of linear but not of circular DNA molecules. A 22 bp homology between the trans DNA and the endogenous DNA was sufficient to initiate recombination but 14 nonhomologous bp at one open end of the SV40 DNA fragments hindered gap repair.
通过免疫荧光染色和DNA印迹分析了显微注射的SV40 DNA片段与COS7细胞内源性SV40 DNA之间的同源重组。时间进程实验表明，转移的（转）DNA与染色体DNA之间的重组在显微注射后约8小时高效发生，且与基因剂量无关。在早期或晚期SV40区域内多达1018个碱基对（bp）的缺失在转移线性而非环状DNA分子后能有效修复。转DNA与内源性DNA之间22 bp的同源性足以启动重组，但SV40 DNA片段一个开放末端的14个非同源bp会阻碍缺口修复。
