Figure 3
Endocannabinoids suppress dauer formation induced by cholesterol depletion. (a) Wild-type control animals grown for two generations in the absence of cholesterol arrest as L2-like larvae (upper micrograph), however, when fed with 2-AG worms form adults (lower micrograph). Representative images from at least three experiments. Scale bars, 0.25 mm. (b) When grown in the absence of cholesterol daf-7 worms form ~65% dauers in the first generation at 15 ºC. This arrest is largely suppressed by the addition of either cholesterol, or DA, or by the endocannabinoid 2-AG. (*) indicates statistically significant difference with solvent control. t-test, p = 0.002. Bars represent mean values and error bars represent standard errors. The number of independent experiments is n = 5 for solvent, and 2-AG, n = 7 for cholesterol, and n = 4 for ∆7-DA. [Cholesterol] = 13 µM. [DA] = 90 nM. [2-AG] = 50 µM. (c) 2-AG suppresses the Daf-c phenotype of ncr-2;ncr-1 at 25 ºC. (*) indicates statistically significant difference with solvent control. Kruskal-Wallis one-way analysis of variance on ranks, p < 0.001 and all pairwise multiple comparison procedures (Student-Newman-Keuls Method), p < 0.05. Bars represent mean values and error bars represent standard errors. The number of independent experiments is n = 6 for all conditions. [Cholesterol] = 13 µM. [DA] = 90 nM. [2-AG] = 50 µM. (d) faah-1 RNAi reduces the percent of dauer formation of strain ncr-2;ncr-1 at 25 ºC. (*) indicates statistically significant difference with solvent empty vector control (EV). One Way Analysis of Variance (p < 0.001) and comparison by Holm-Sidak method, p < 0.001 in both cases. Bars represent mean values and error bars represent standard errors. The number of independent experiments is n = 6 for all conditions tested. [DA] = 90 nM.
