Keto-enol insecticides disrupt ovarian Wnt/armadillo signaling and redox balance, inducing generational toxicity in Drosophila melanogaster

This study is the first to detect Wnt/armadillo signaling pathway activity in the germarium of Fz3-RFP transgenic Drosophila melanogaster females orally exposure to sublethal concentrations of the keto-enol insecticides Movento® 240 SC (0, 11.2, 22.4, 37.3 mg/L) and Envidor® 240 SC (0, 12.3, 24.6, 41.1 mg/L) for 72 h. Both insecticides induced irregular overexpression of receptor Fz3 in regions 1 and 2a of the germarium, accompanied by morphological changes, tissue disorganization, and reduced cell number compared to controls. In wild-type females, oxidative stress was evidenced by increased MDA (malondialdehyde) levels and elevated antioxidant enzyme activities of SOD (superoxide dismutase) and CAT (catalase) following exposure. These effects correlated with reduced fertility, reproduction, and generational alterations, assessed via oviposition and hatching rates, and larval development (L1, L2, L3). Movento® 240 SC and Envidor® 240 SC significantly increased MDA (0.32-0.78 and 0.21-0.57 nmol mg^-1 protein) and enzymatic activities of CAT (0.16-0.20 and 0.13-0.15 U mg^-1 protein) and SOD (0.40-0.69 and 0.19-0.54 U mg^-1 protein), respectively, compared to controls. Oviposition and hatching rates decreased to 22-62 % and 47-86 %. Larval progression from L1 to L3 was delayed, with reductions of 30-97 %. Additionally, 60 % of L1 larvae from females exposed to 22.4 and 37.3 mg/L Movento® 240 SC and 24.6 and 41.1 mg/L Envidor® 240 SC exhibited locomotor defects, including reduced head-thrust intensity, body curling, and diminished burrowing, highlighting significant generational impacts.