Small mosquitoes, large implications: crowding and starvation affects gene expression and nutrient accumulation in Aedes aegypti

Abstract

BackgroundEnvironmental factors such as temperature, nutrient availability, and larval density determine the outcome of postembryonic development in mosquitoes. Suboptimal temperatures, crowding, and starvation during the larval phase reduce adult mosquito size, nutrient stores and affect vectorial capacity.MethodsIn this study we compared adult female Aedes aegypti, Rockefeller strain, raised under standard laboratory conditions (Large) with those raised under crowded and nutritionally deprived conditions (Small). To compare the gene expression and nutritional state of the major energy storage and metabolic organ, the fat body, we performed transcriptomics using Illumina based RNA-seq and metabolomics using GC/MS on females before and 24 hours following blood feeding.ResultsAnalysis of fat body gene expression between the experimental groups revealed a large number of significantly differentially expressed genes. Transcripts related to immunity, reproduction, autophagy, several metabolic pathways; including amino acid degradation and metabolism; and membrane transport were differentially expressed. Metabolite profiling identified 60 metabolites within the fat body to be significantly affected between small and large mosquitoes, with the majority of detected free amino acids at a higher level in small mosquitoes compared to large.ConclusionsGene expression and metabolites in the adult fat body reflect the individual post-embryonic developmental history of a mosquito larva. These changes affect nutritional storage and utilization, immunity, and reproduction. Therefore, it is apparent that changes in larval environment due to weather conditions, nutrition availability, vector control efforts, and other factors can affect adult vectorial capacity in the field.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0863-9) contains supplementary material, which is available to authorized users.

Reconfiguration of the immune system network during food limitation in the caterpillarManduca sexta

“…In fact, absent-nutrition caterpillars showed little, if any, inducible responses, especially when the fact that their immune genes are constitutively upregulated was taken into account (Figs 4 and 5). Food-deprived Drosophila (Becker et al, 2010) and mosquitoes (Aedes aegypti; Price et al, 2015) also show a similar shift towards a more constitutive expression of inducible antimicrobial genes (Becker et al, 2010), suggesting that this may be a common response in insects.…”

Predator stress-induced immunosuppression: trade-off, immune redistribution or immune reconfiguration?

“…Drosophila melanogaster : Becker et al, 2010;Tsuzuki et al, 2012; mosquitoes (Aedes aegypti): Price et al, 2015; and M. sexta 5th instar caterpillars: Adamo et al, 2016a,b). Specific intracellular pathways induce antimicrobial peptide expression and production without the usual activation of pathogen recognition pathways (e.g.…”

Larval stress alters dengue virus susceptibility in Aedes aegypti (L.) adult females

“…Further, nutrient availability and daily temperature regimes can vary significantly among active breeding containers distributed in the same household area (Hemme et al, 2009). Despite shared genetic ancestry, larval stress has proven a critical influence on adult phenotype, which in turn is strikingly correlated with a suite of life history traits including vector competence (De Jesus and Reiskind, 2016; Honek, 1993; Mourya et al, 2004; Ponlawat and Harrington, 2007; Price et al, 2015; Schluter et al, 1991; Vantaux et al, 2016). In a previous study, our laboratory demonstrated the G × E influence of larval stress on adult body size (Schneider et al, 2011).…”