Genetic background determines Drosophila response to nicotine.

(A) Dose response of w¹¹¹⁸ flies to different concentrations of nicotine. The time needed for half of the flies to recover from a given concentration of nicotine exposure is defined as Half Recovery Time (HRT), note that mock exposure of flies (0 ng, closed circles) allows flies to recover nearly immediately. (B) HRTs are shown for different fly genotypes: w¹¹¹⁸ and Ore-R are controls, L70 has an insertion located at the 5’ of the miR-310^c, F1.1 is a revertant line, where the P-element insertion of L70 line has been precisely excised. L4 line has an insertion in esg. L70 and L4 showed nicotine hypersensitivity. (C) Schematic representation of the L4 P{GawB} insertion. The triangle represents the insertion site according to fly-base standard genome coordinates (release version 6). Zinc fingers are denoted by orange bands, the site of the esg^35ce-3 mutation is shown by an arrow. (D) Schematic representation of the L70 P{GawB} insertion. The inverted triangle represents the insertion site according to fly-base standard genome coordinates (release version 6). The arrow shows the miR-310^c cistron transcription initiation site. (E) L70 and L4 insertion lines are sensitive to chronic nicotine exposure. Restricted mean lifespan of mutant genotypes are significantly reduced compared to w¹¹¹⁸ when maintained in standard cornmeal food, supplemented with 0.5 mg/ml nicotine. All experiments were repeated at least 3 times with an n ≥ 100 flies. * = P≤ 0.01, ** = P≤ 0.001, **** = P<< 0.001, ns = not significant.