大背景：Sexual reproduction constrains progeny to inherit allelic genes from both parents. Selective acquisition of target genes from only one parent in the F1 generation of plants has many potential applications including the elimination of undesired alleles and acceleration of trait stacking. 

小背景+问题：CRISPR/Cas9-based gene drives can generate biased transmission of a preferred allele and convert heterozygotes to homozygotes in insects and mice, but similar strategies have not been implementable in plants because of a lack of efficient homology-directed repair (HDR). 

结果1-构建基因驱动：Here, we place a gene drive, which consists of cassettes that produce Cas9, guide RNAs (gRNA), and fluorescent markers, into the CRYPTOCHROME 1 (CRY1) gene through CRISPR/Cas9-mediated HDR, resulting in cry1drive lines. 

结果2-F1代纯合：After crossing the cry1drive/cry1drive lines to wild type, we observe F1 plants which have DNA at the CRY1 locus from only the cry1drive/cry1drive parent. 

结果3-非自主性反式基因驱动：Moreover, a non-autonomous trans-acting gene drive, in which the gene drive unit and the target gene are located on different chromosomes, converts a heterozygous mutation in the target gene to homozygous. 

结论：Our results demonstrate that homozygous F1 plants can be obtained through zygotic conversion using a CRISPR/Cas9-based gene drive.

 摘 要 

有性生殖限制了子代，必须从双亲中各自继承一个等位基因。在植物F1代中，仅从单个亲本中选择性获得目标基因具有许多潜在的应用，包括消除劣势等位基因和加速性状聚合。基于CRISPR/Cas9的基因驱动在昆虫和老鼠中，能够产生优势等位基因的偏向性传递，并且将杂合子转变为纯合子；但是，由于植物缺少高效的同源指导修复HDR，相关研究还未见报道。本文中，作者通过CRISPR/Cas9介导的HDR，将一段包含能够产生Cas9、gRNA和荧光标记的基因盒置入了CRY1基因区，形成了cry1drive株系。接着，作者通过杂交cry1drive/cry1drive株系和WT野生型，作者发现F1代中存在CRY1位点只来自于一方亲本，即cry1drive/cry1drive株系的个体。此外，作者还构建了一个非自主性反式作用基因驱动，即基因驱动单元与目标基因分散在不同的染色体上，结果发现成功将目标基因的杂合突变转变成了纯合突变。本文的研究揭示了，CRISPR/Cas9介导的基因驱动可以通过合子转化，获得F1代纯合。