Sublethal metal stress response of larvae of Aedes aegypti.

摘要

Aedes aegypti (Diptera: Culicidae) has adapted to urban environments. The urbanization process provides suitable habitats for this disease vector, subsequently increasing the probability of the transmission of pathogens in high-density environments. Urban environments provide metal-stressed larval habitats. However, little is known about the physiological cost of metal stress or how this might affect the performance of this mosquito species. The present study aims to characterize the sublethal physiological consequences of metal stress in Aedes aegypti. Various parameters of mosquito physiology under larval metal stress are assessed, including larval metallothionein expression and the effects of larval metal stress on adult performance and their progeny. The results show that environmentally relevant larval metal stress compromises larval and adult development and performance, and also results in larval metal tolerance along with an increase in lipid consumption. These performance costs are coupled with a dramatic increase in metallothionein expression in the midgut. Metal stress results in a lowered adult body mass and neutral storage lipids at emergence, starvation tolerance, fecundity and starvation tolerance of offspring compared with non-metal-stressed individuals. Ironically, larval metal stress results in increased adult longevity. Taken together, these findings indicate that even low levels of environmentally relevant larval metal stress have considerable physiological consequences for this important disease vector.