Insertion mutants of the <i>Drosophila FoxP</i> gene affect isoform expression and flight performance.

<p><b>a</b>, Rooted phylogenetic tree using the genomic sequence of the <i>Drosophila FoxP</i> gene (see Materials and Methods). The single invertebrate FoxP gene probably corresponds to the ancestral form from which the four vertebrate genes have arisen by serial duplication. <b>b</b>, Location of the three insertions (black triangles) and qRT-PCR primer pairs (grey arrows) on the genomic structure of the <i>dFoxP</i> gene (left). Structure of the three cloned transcripts (right). IR: intron retention; FH: Forkhead-Box Domain. <b>c</b>, Expression levels of the three <i>dFoxP</i> isoform mRNAs in heads of Canton S wildtype flies and of the three insertion lines using qRT-PCR. Horizontal lines denote averages, individual circles, trinagles and squares constitute different biological replicates. * - p<0.05, ** - p<0.01, *** - p<0.001. <b>d</b>, Flight performance of Canton S wildtype flies and the three insertion lines. Asterisk denotes statistical significance compared to Canton S control flies (Kruskal-Wallis ANOVA: H(3, N = 119) = 46.02 p<0.0001, 3955: R = 77.0, p<0.4; f03746: R = 50.9, p<0.00004; c03619: R = 37.0, p<0.00001). Number of animals: 18–37. For full flight performance data see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100648#pone.0100648.s001" target="_blank">Fig. S1</a>.</p>