Kwon Erika M, Connelly John P, Hansen Nancy F, Donovan Frank X, Winkler Thomas, Davis Brian W, Alkadi Halah, Chandrasekharappa Settara C, Dunbar Cynthia E, Mullikin James C, Liu Paul
Oncogenesis and Development Section, National Human Genome Research Institute, NIH, Bethesda, MD 20892.
Comparative Genomics Unit, NIH Intramural Sequencing Center, National Human Genome Research Institute, NIH, Bethesda, MD 20892.
Proc Natl Acad Sci U S A. 2017 Feb 21;114(8):1964-1969. doi: 10.1073/pnas.1616035114. Epub 2017 Feb 6.
Genome integrity of induced pluripotent stem cells (iPSCs) has been extensively studied in recent years, but it is still unclear whether iPSCs contain more genomic variations than cultured somatic cells. One important question is the origin of genomic variations detected in iPSCs-whether iPSC reprogramming induces such variations. Here, we undertook a unique approach by deriving fibroblast subclones and clonal iPSC lines from the same fibroblast population and applied next-generation sequencing to compare genomic variations in these lines. Targeted deep sequencing of parental fibroblasts revealed that most variants detected in clonal iPSCs and fibroblast subclones were rare variants inherited from the parental fibroblasts. Only a small number of variants remained undetectable in the parental fibroblasts, which were thus likely to be de novo. Importantly, the clonal iPSCs and fibroblast subclones contained comparable numbers of de novo variants. Collectively, our data suggest that iPSC reprogramming is not mutagenic.
近年来，诱导多能干细胞（iPSC）的基因组完整性已得到广泛研究，但iPSC是否比培养的体细胞含有更多基因组变异仍不清楚。一个重要问题是在iPSC中检测到的基因组变异的起源——iPSC重编程是否会诱导此类变异。在这里，我们采用了一种独特的方法，从同一个成纤维细胞群体中衍生出成纤维细胞亚克隆和克隆iPSC系，并应用下一代测序技术来比较这些细胞系中的基因组变异。对亲本成纤维细胞进行靶向深度测序发现，在克隆iPSC和成纤维细胞亚克隆中检测到的大多数变异是从亲本成纤维细胞继承而来的罕见变异。只有少数变异在亲本成纤维细胞中未被检测到，因此这些变异可能是新生的。重要的是，克隆iPSC和成纤维细胞亚克隆中新生变异的数量相当。总体而言，我们的数据表明iPSC重编程不会诱发突变。
