Fig. 1. Experimental design of the split gene-drive system in essential loci.

a Schematic of the genetic constructs engineered and tested in the study. All constructs contain a recoded cDNA of the target gene that restores its functionality upon insertion of the transgene, a specific gRNA, and expression of 3xP3-tdTomato. Static Cas9 lines encode a nanos or vasa-driven Cas9 and a selectable marker, Opie2-dsRed or 3xP3-GFP, respectively. b Outline of the genetic cross schemes used to demonstrate the driving efficiency of each sGD, comparing systems where the sGD, Cas9 and wildtype (WT, +) are located in the same (right panel) or different chromosomes (left panel). F₁ trans-heterozygotes (carriers of both Cas9 and sGD in trans) were singly crossed to WT individuals to assess germline transmission rates by scoring % of the fluorescence markers in F₂ progeny. The conversion event at the sGD locus is shown with a triangle in F₁ individuals. c Overview of how data is plotted throughout the paper. F₁ germline inheritance is plotted in two independent columns, one that refers to the static Cas9, which should be inherited at Mendelian ratios since it does not have driving capacity, and a second column that displays the biased inheritance of the sGD transgene. Graph contains no empirical data. d Chromosomal location and insertion sites of all sGD and static Cas9 transgenes in the Drosophila melanogaster genome.