Mechanical Permeabilization as a New Method for Assessment of Mitochondrial Function in Insect Tissues.

Respirometry analysis is an effective technique to assess mitochondrial physiology. Insects are valuable biochemical models to understand metabolism and human diseases. Insect flight muscle and brain have been extensively used to explore mitochondrial function due to dissection feasibility and the low sample effort to allow oxygen consumption measurements. However, adequate plasma membrane permeabilization is required for substrates/modulators to reach mitochondria. Here, we describe a new method for study of mitochondrial physiology in insect tissues based on mechanical permeabilization as a fast and reliable method that do not require the use of detergents for chemical permeabilization of plasma membrane, while preserves mitochondrial integrity.

A simple and reliable method for longitudinal assessment of untethered mosquito induced flight activity.

Aedes aegypti adult females are key vectors of several arboviruses and flight activity plays a central role in mosquito biology and disease transmission. Available methods to quantify mosquito flight usually require special devices and mostly assess spontaneous locomotor activity at individual level. Here, we developed a new method to determine longitudinal untethered adult A. aegypti induced flight activity: the INduced FLight Activity TEst (INFLATE). This method was an adaptation of the "rapid iterative negative geotaxis" assay to assess locomotor activity in Drosophila and explore the spontaneous behavior of mosquitoes to fly following a physical stimulus. Insects were placed on a plastic cage previously divided in four vertical quadrants and flight performance was carried out by tapping cages towards the laboratory bench. After one minute, the number of insects per quadrant was registered by visual inspection and categorized in five different scores. By using INFLATE, we observed that flight performance was not influenced by repeated testing, sex or 5% ethanol intake. However, induced flight activity was strongly affected by aging, blood meal and inhibition of mitochondrial complex I. This simple and rapid method allows the longitudinal assessment of induced flight activity of multiple untethered mosquitoes and may contribute to a better understanding of A. aegypti dispersal biology.