Fig 8. Model for wtf drive suppression.

(A) Sp wtf18-2 likely arose from a non-allelic gene conversion event between the Sp wtf18 allele present in the reference genome and Sp wtf13. This gene conversion event provided Sp wtf18 with the exon 6 present in Sp wtf13. The non-allelic conversion event happened from positions 1,580,047–1,580,343 to positions 1,806,929–1,807,206. This track includes part of wtf13 exon 5, intron 5, exon 6 and 3’ UTR region. (B) In wtf13 heterozygous diploids (wtf13+/ wtf13-), Sp Wtf13^poison has the ability to kill every spore, but the Sp Wtf13^antidote recognizes the Sp Wtf13^poison protecting the spores that inherit the Sp wtf13+ allele. (C) In Sp wtf13+/ Sp wtf18+ diploids, the spores that inherit the wtf13+ allele are protected from the Wtf13^poison by the Sp Wtf13^antidote. The two spores that inherit the Sp wtf18+ allele die because Wtf18 does not neutralize the Sp Wtf13^poison. (D) In Sp wtf13+/ Sp wtf18-2+ diploids, the spores that inherit the Sp wtf18-2+ allele are protected from the Wtf13^poison because Sp Wtf18-2 makes an antidote capable of neutralizing the Sp Wtf13^poison. Both Sp wtf13 and Sp wtf18 alleles are depicted at the same locus on opposite haplotypes, like the experiments in Fig 2A.