Hasty P, Rivera-Pérez J, Bradley A
Department of Human and Molecular Genetics, Baylor College of Medicine, TX 77030, USA.
Nucleic Acids Res. 1995 Jun 11;23(11):2058-64. doi: 10.1093/nar/23.11.2058.
Recombination of an insertion vector into its chromosomal homologue is a conservative event in that both the chromosomal and the vector sequences are preserved. However, gene conversion may accompany homologous recombination of an insertion vector. To examine gene conversion in more detail we have determined the targeting frequencies and the structure of the recombinant alleles generated with a series of vectors which target the hprt gene in embryonic stem cells. We demonstrate that gene conversion of the introduced mutation does not significantly limit homologous recombination and that gene conversion occurs without a sequence specific bias for five different mutations. The frequency of the loss of a vector mutation and the gain of a chromosomal sequence is inversely proportional to the distance between the vector mutation and the double-strand break. The loss of a chromosomal sequence and the gain of a vector mutation occurs at a low frequency.
插入载体与其染色体同源物的重组是一个保守事件，因为染色体序列和载体序列都会保留下来。然而，基因转换可能伴随插入载体的同源重组。为了更详细地研究基因转换，我们确定了一系列靶向胚胎干细胞中hprt基因的载体所产生的靶向频率和重组等位基因的结构。我们证明，导入突变的基因转换不会显著限制同源重组，并且对于五种不同的突变，基因转换的发生没有序列特异性偏向。载体突变的丢失和染色体序列的获得频率与载体突变和双链断裂之间的距离成反比。染色体序列的丢失和载体突变的获得发生频率较低。
