Figure 3. Free-flight to plain food in desat1 transgenics.

(a) Schematic representation of the molecular structure of the desat1 pheromonal gene. The inverted triangle (1573) indicates the PGal4 element inserted in desat1 acting both as a mutation (in homozygous 1573/1573 flies) and as a Gal4 driver used to target the UAS-desat1-RNAi transgene (1573/RNAi). The complete desat1 regulatory region (6908 bp) was also used to target UAS-desat1-RNAi. (b–e) The four histograms series represent four free-flight features (see Fig. 1a) toward plain food (for the response to water, see Supplementary Fig. S2). The simplified genotypes are indicated below each pair of bars. Beside the wild-type genotype (+/+), flies either contained one or two copies of the 1573 inserted element (1573/+, 1573/1573, respectively). We also targeted the UAS-desat1-RNAi transgene with a single copy of the 1573 allele (1573/RNAi), or of the complete desat1 regulatory region fused with Gal4 (6908-Gal4). In the latter genotype (6908/RNAi), adult rescue was obtained with C18:1-rich diet provided only during larval stage (L) or during both larval and adult stages (L + A). Given their intricated relationship, the statistical difference of all genotypes was simultaneously tested. For details, please refer to Fig. 1 legend and Supplementary Table S3. N = 40–65.