Figure 1.

Generation of new Rtnl1 null mutant alleles. For the different Rtnl1 splice variants, blue boxes indicate coding sequence, broken lines introns, light orange boxes UTR sequences, and arrows the direction of transcription. Green triangle indicates the position of the Rtnl1::YFP exon trap insertion (CPTI001291). Genomic coordinates are from Release 6.26 of the Drosophila melanogaster genome (http://flybase.org). Magnified detail shows exons encoding Rtnl1 intramembrane domains (green; bottom), locations recognized by gRNAs, the Rtnl1¹⁸ lesion, and the 8-bp (Rtnl1⁴) and the 1-bp (Rtnl1::YFP³) frameshift deletions, generated at the site of the upstream gRNA on Rtnl1⁺ and Rtnl1^CPTI001291 backgrounds respectively, but not used further in this work. The length of each mutated region is shown. In Rtnl1¹⁸, the region encoding the first intramembrane domain is completely disrupted by an inversion, while the initial part of the sequence encoding the second intramembrane domain is absent due to a deletion and frameshift (see Fig. S1 for more molecular details of alleles).