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


METHODS
In 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.


RESULTS
Analysis 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.


CONCLUSIONS
Gene 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.
Department of Biology, New Mexico State University, Las Cruces, NM, USA. daprice@nmsu.edu.|Molecular Biology Program, New Mexico State University, Las Cruces, USA. daprice@nmsu.edu.
David P
DP
Price
National Center for Genome Resources, Santa Fe, NM, USA. fds@ncgr.org.
Faye D
FD
Schilkey
Roy J. Carver Biotechnology Center, University of Illinois, Urbana-Champaign, Illinois, USA. ulanov@illinois.edu.
Alexander
A
Ulanov
Department of Biology, New Mexico State University, Las Cruces, NM, USA. immoh@nmsu.edu.|Molecular Biology Program, New Mexico State University, Las Cruces, USA. immoh@nmsu.edu.
Immo A
IA
Hansen
D000330:Aedes / Q000235:genetics / Q000502:physiology*; D000818:Animals; D003441:Crowding; D005216:Fat Body / Q000737:chemistry / Q000502:physiology; D005260:Female; D005502:Food; D008401:Gas Chromatography-Mass Spectrometry; D015870:Gene Expression; D020869:Gene Expression Profiling; D055432:Metabolomics; D013217:Starvation