Formation of large deletions by illegitimate recombination in the HPRT gene of primary human fibroblasts.
Formation of large deletions by illegitimate recombination in the HPRT gene of primary human fibroblasts.
复制标题
原代人成纤维细胞 HPRT 基因中非法重组形成大缺失。
DOI：
10.1073/pnas.90.4.1392
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发表时间：
1993
影响因子：
11.1
通讯作者：
John Thacker
中科院分区：
文献类型：
--
作者：
Tracy Morris;John Thacker
从未经处理和X射线照射的原代人成纤维细胞培养物中分离到HPRT基因突变体，并鉴定出携带大量缺失的突变体。用基于聚合酶链式反应的方法定位缺失的断裂点，并对4个不同突变体的缺失连接进行了测序。ALU重复序列与这些连接中的三个连接的一端相关，但在每种情况下，在另一端都没有发现重复序列。在缺失断裂点发现的序列特征包括特别是短的正向和反向重复，它们可能错配以促进非法重组。一个突变体在缺失连接处插入了额外的碱基；这些碱基与紧邻连接处的序列形成了直接重复，这表明在缺失形成过程中断裂DNA的模板修复机制。
HPRT gene mutants were isolated from untreated and x-irradiated cultures of primary human fibroblasts, and mutants carrying large deletions were identified. The breakpoints of the deletions were mapped by methods based on the polymerase chain reaction, and the deletion junctions of four different mutants were sequenced. Alu repeats were associated with one end of three of these junctions, but in each case repeat sequences were not found at the other end. Sequence features found at the deletion breakpoints included in particular short direct and inverted repeats, which may mispair to promote illegitimate recombination. One mutant had additional bases inserted at the deletion junction; these bases formed a direct repeat with a sequence immediately adjacent to the junction, suggesting a mechanism of templated repair of broken DNA in deletion formation.