RT Journal Article SR Electronic T1 Reducing resistance allele formation in CRISPR gene drives JF bioRxiv FD Cold Spring Harbor Laboratory SP 150276 DO 10.1101/150276 A1 Jackson Champer A1 Jingxian Liu A1 Suh Yeon Oh A1 Riona Reeves A1 Anisha Luthra A1 Nathan Oakes A1 Andrew G. Clark A1 Philipp W. Messer YR 2017 UL http://biorxiv.org/content/early/2017/06/14/150276.abstract AB CRISPR gene drives can efficiently convert heterozygous cells with one copy of the drive allele into homozygotes, thereby enabling super-Mendelian inheritance. This mechanism could be used, for example, to rapidly disseminate a genetic payload through a population, promising novel strategies for the control of vector-borne diseases. However, all CRISPR gene drives tested have produced significant quantities of resistance alleles that cannot be converted to drive alleles and would likely prevent these drives from spreading in a natural population. In this study, we assessed three strategies for reducing resistance allele formation. First, we directly compared drives with the nanos and vasa promoters, which showed that the vasa drive produced high levels of resistance alleles in somatic cells. This was not observed in the nanos drive. Another strategy was the addition of a second gRNA to the drive, which both significantly increased the drive conversion efficiency and reduced the formation rate of resistance alleles. Finally, to minimize maternal carryover of Cas9, we assessed the performance of an autosomal drive acting in the male germline, and found no subsequent formation of resistance alleles in embryos. Our results mark a step toward developing effective gene drives capable of functioning in natural populations and provide several possible avenues for further reduction of resistance rates.