Fig. 1.

TS-ClvR design and concept. (A) TS-ClvR drive element comprised of Cas9/gRNAs targeting an essential gene and a recoded Rescue (not recognized by Cas9/gRNAs), which includes a TS-intein within its coding region. After translation, the TS-intein can splice itself out to yield a functional Rescue protein. (B) Population suppression with a TS-ClvR. TS-ClvR–bearing flies (red) are released into a WT population (yellow). The TS-ClvR selfish element spreads into the population at the cost of WT. Once the TS-ClvR element has reached genotype fixation (all individuals in the population have at least one copy of TS-ClvR), all functional endogenous copy of the essential gene targeted by TS-ClvR will have been mutated to LOF. At this point, the conditional TS-Rescue within the ClvR element provides the only source of essential gene function in the population, making it subject to a collapse in response to a temperature shift.