The piggyBac Transposon Displays Local and Distant Reintegration Preferences and Can Cause Mutations at Noncanonical Integration Sites
The piggyBac Transposon Displays Local and Distant Reintegration Preferences and Can Cause Mutations at Noncanonical Integration Sites
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DOI：
10.1128/mcb.00670-12
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发表时间：
2013-04-01
影响因子：
5.3
通讯作者：
Bradley, Allan
中科院分区：
文献类型：
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作者：
Li, Meng Amy;Pettitt, Stephen J.;Bradley, Allan
DNA转座子piggyBac被广泛用作哺乳动物实验系统中转基因、诱变和基因组工程的工具。我们的特点是全基因组插入位点偏好的piggyBac测序一个大的整合位点所产生的转座从两个独立的基因组位点和质粒供体在小鼠胚胎干细胞。我们发现，piggyBac优先整合本地切除位点时，动员从染色体位置和确定其他非本地区域的基因组插入频率升高。piggyBac插入与表达的基因和开放染色质结构的标记相关，并从异染色质中排除。在核苷酸水平上，piggyBac倾向于在更广泛的富含GC的背景下插入富含TA的区域。我们还发现piggyBac可以以低频率（2%）插入到其已知TTAA插入位点以外的位点。这样的插入引入错配，所述错配用宿主细胞修复途径的特征来修复。转座子可以从具有所观察到的非典型侧翼区的质粒中动员出来，这表明piggyBac可以在基因组中产生点突变。
The DNA transposon piggyBac is widely used as a tool in mammalian experimental systems for transgenesis, mutagenesis, and genome engineering. We have characterized genome-wide insertion site preferences of piggyBac by sequencing a large set of integration sites arising from transposition from two separate genomic loci and a plasmid donor in mouse embryonic stem cells. We found that piggyBac preferentially integrates locally to the excision site when mobilized from a chromosomal location and identified other nonlocal regions of the genome with elevated insertion frequencies. piggyBac insertions were associated with expressed genes and markers of open chromatin structure and were excluded from heterochromatin. At the nucleotide level, piggyBac prefers to insert into TA-rich regions within a broader GC-rich context. We also found that piggyBac can insert into sites other than its known TTAA insertion site at a low frequency (2%). Such insertions introduce mismatches that are repaired with signatures of host cell repair pathways. Transposons could be mobilized from plasmids with the observed noncanonical flanking regions, indicating that piggyBac could generate point mutations in the genome.