Lin Chun-Chieh, Potter Christopher J
The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
G3 (Bethesda). 2016 Nov 8;6(11):3685-3691. doi: 10.1534/g3.116.034884.
The CRISPR/Cas9 system has revolutionized genomic editing. The Cas9 endonuclease targets DNA via an experimentally determined guide RNA (gRNA). This results in a double-strand break at the target site . We generated transgenic in which the CRISPR/Cas9 system was used to target a transgene To our surprise, progeny whose genomes did not contain CRISPR/Cas9 components were still capable of mutating sequences. We demonstrate this effect was caused by maternal deposition of Cas9 and gRNAs into the embryo, leading to extensive mutations in both somatic and germline tissues. This serves as a cautionary observation on the effects of maternal contributions when conducting experiments using genomically encoded CRISPR/Cas9 components. These results also highlight a mode of artificial inheritance in which maternal contributions of DNA editing components lead to transmissible mutant defects even in animals whose genomes lack the editing components. We suggest calling this a dominant maternal effect to reflect it is caused by the gain of maternally contributed products. Models of CRISPR-mediated gene drive will need to incorporate dominant maternal effects in order to accurately predict the efficiency and dynamics of gene drive in a population.
CRISPR/Cas9系统彻底改变了基因组编辑。Cas9核酸内切酶通过实验确定的引导RNA（gRNA）靶向DNA。这会导致靶位点出现双链断裂。我们构建了转基因品系，其中使用CRISPR/Cas9系统靶向一个转基因。令我们惊讶的是，其基因组中不包含CRISPR/Cas9组件的后代仍然能够使序列发生突变。我们证明这种效应是由Cas9和gRNA通过母体沉积到胚胎中引起的，导致体细胞和生殖系组织中出现广泛的突变。这是在使用基因组编码的CRISPR/Cas9组件进行实验时，关于母体贡献影响的一个警示性观察结果。这些结果还突出了一种人工遗传模式，即DNA编辑组件的母体贡献导致即使在基因组缺乏编辑组件的动物中也会出现可遗传的突变缺陷。我们建议将此称为显性母体效应，以反映它是由母体贡献产物的增加所引起的。CRISPR介导的基因驱动模型需要纳入显性母体效应，以便准确预测种群中基因驱动的效率和动态。
