Loss of <i>aak-2</i> mimics increased serotonin signaling.

<p><b>A.. </b><i>aak-2</i> mutants and wild type animals (WT) treated with exogenous serotonin (5 mM) or fluoxetine (50 µg/mL) have fewer body bends when removed from food. Pan-neuronal reconstitution of <i>aak-2</i> (p<i>unc-119</i>) restores wild type body bends to <i>aak-2</i> mutants. n = 10, *p<0.05, one-way ANOVA with Bonferroni correction for multiple comparisons. <b>B.. </b><i>aak-2</i> deficient animals have reduced hypodermal BODIPY fluorescence relative to WT. Wild type BODIPY staining is restored to <i>aak-2</i> mutants when <i>aak-2</i> is reconstituted in the nervous system (p<i>unc-119</i>). n = 10, ***p<0.001, one-way ANOVA with Bonferroni correction for multiple comparisons. <b>C.</b> Wild type animals treated with 5 mM 5-HT have significantly lower triglycerides per protein (TAG/protein) compared to sham treatment as determined by total lipid extraction followed by Thin Layer Chromatography. Sham treated <i>aak-2</i> mutants already have significantly lower TAG/protein compared to WT and 5 mM 5-HT treatment does not result in further reduction. TAG/protein levels of 5-HT treated WT are not significantly different than those of <i>aak-2</i> +/− 5-HT. n = 3, *p<0.05, Student's t-test. <b>D-E.</b> Quantitation of signal intensities of Coherent anti-Stokes Raman Scattering, CARS, of WT and <i>aak-2</i> mutants +/− 5 mM 5-HT treatment. 5-HT treatment lowered the CARS signal intensities from the intestinal (D) and head hypodermal (E) regions of WT animals. <i>aak-2</i> mutants had lower signal intensities relative to WT, which was not further reduced by 5 mM 5-HT treatment. Signal intensities of 5-HT treated WT were not significantly different than those of <i>aak-2</i> +/− 5-HT. n = 5, *p<0.01, Student's t-test. <b>F.</b> Loss of <i>aak-2</i> or 5 mM 5-HT treatment caused elevated oxygen consumption. WT and <i>aak-</i>2 mutants (n = 800 per genotype) were sham treated. Data are expressed as a percentage of WT. Error bars represented +/− SEM. **p < 0.01 versus sham treated WT, one-way ANOVA with Bonferroni correction for multiple comparisons <b>G-H.</b> Loss of <i>cpt-1a</i> via RNAi restores wild type BODIPY staining to hypodermis (white arrow) and intestine (yellow arrow) of <i>aak-2</i> mutants. Representative BODIPY staining images (G) and corresponding quantitations (H) are shown. n = 5, *p<0.05, Student's t-test.</p>