Fig. 1: Mechanism of the TARE drive.

In the germline of drive/wild-type heterozygotes, wild-type copies will usually undergo cleavage followed by homology-directed repair or end-joining, either of which will result in a disrupted target gene and loss of function. Meiosis and fertilization (shown here by a wild-type gamete) then occur. In the progeny of females with the drive, maternally deposited Cas9 and gRNA will cleave most wild-type alleles, which will become disrupted after end-joining repair. Any individual that inherited two recessive lethal disrupted alleles of the target gene will be nonviable, which will lead to a systematic increase of the relative frequency of the drive allele over time. Dotted arrows specify events that should occur less frequently.