Relative expression of (A) CYP19 coding region (nonpromoter-specific or total), and CYP19 transcripts derived from promoters (B) PII, (C) I.3, and (D) I.7 in Hs578t cells exposed to thiacloprid () or imidacloprid () in the presence or absence of selective inhibitors of the PLC (U73122, ) or MEK/MAPK 1/3 (PD98059, ) signaling pathways. Relative transcript levels are expressed as a percentage (%) of the response of Hs578t cells exposed to thiacloprid or imidacloprid (100%). Experiments were performed in triplicate with three different cell passages; per experiment, each treatment was tested in triplicate. *, ; **, ; ***, . Statistically significant difference between inhibitor pretreatment and neonicotinoid treatment alone (Student t-test).