Razanamparany V, Bégueret J
Laboratoire de Génétique, UA CNRS 542, Talence, France.
Gene. 1988 Dec 30;74(2):399-409. doi: 10.1016/0378-1119(88)90173-4.
Transformation of the ura5-6 mutant strain of Podospora anserina with a recombinant vector carrying the ura5+ gene often results in the integration of the transforming plasmid by non-homologous recombination outside of the genomic ura5 locus. To investigate the mechanism of such integration, we rescued the integrated plasmid from three transformants. In two cases, the rescued plasmid was highly altered compared with the original transforming vector. We cloned the junctions between plasmidic DNA and genomic DNA of the transformants and determined their nucleotide sequences. It was found that there was little homology between plasmidic and genomic DNA sequences. Moreover, in all cases deletions of plasmid sequences at the integration site had occurred. These rearrangements can be explained by the formation of multimeric plasmids prior to integration.
用携带ura5⁺基因的重组载体转化嗜热栖粪壳菌的ura5 - 6突变菌株，常常会导致转化质粒通过非同源重组整合到基因组ura5位点之外。为了研究这种整合的机制，我们从三个转化体中拯救出了整合质粒。在两个案例中，拯救出的质粒与原始转化载体相比有很大改变。我们克隆了转化体中质粒DNA与基因组DNA之间的连接点，并确定了它们的核苷酸序列。结果发现，质粒DNA与基因组DNA序列之间几乎没有同源性。此外，在所有案例中，整合位点处的质粒序列都发生了缺失。这些重排现象可以通过整合前多聚体质粒的形成来解释。
