Fig 2. Nicotine exposure during the larval stage accounts for nicotine's effects on survival and developmental delay.

Flies were reared on control or nicotine food during specific stages of development and the number of eclosed flies over time was counted to estimate survival and developmental delay. (A) Percent survival by 16 days ael was significantly reduced between control (black bar) and flies reared on nicotine food throughout development, or only during the larval stages. Nicotine exposure during embryogenesis or metamorphosis had no effect. (B) ET50 was significantly longer than control ET50 with nicotine exposure throughout development, or only during larval stages. Exposure during embryogenesis or metamorphosis did not have an effect on ET50. (A,B) Kruskal-Wallis followed by Dunn-Bonferroni pairwise comparison; only comparisons against control are shown; n ≥ 25 samples per condition from n ≥ 4 independent experiments. Each sample is a fly vial with 50–75 animals exposed to nicotine.