For each strain, total RNA was extracted from three pools of 10, three day old, non blood-fed females using Pico PureTM RNA Isolation Kit (Applied biosystems, Foster city, CA, USA). The strains were reared in parallel to minimize variation resulting from breeding conditions. Each biological replicate consisted of mosquitoes from distinct generations to control for stochastic variations. The quality and concentration of RNA was assessed using a 2100 Bioanalyzer (Agilent technologies, Santa Clara, CA, USA).
Insecticide susceptibility bioassays with 0.75% permethrin were carried out using 2-5 day-old F1 adults following the WHO protocol (WHO 1998). Mortality was assessed 24h after exposure. Unexposed mosquitoes were also 2-5 day-old F1 adults stored at -80C without any exposure to insecticide
The field and the FANG strains were reared under standard conditions (25 + 2C, 70-80 % RH) in insectaries.