Mosquitoes are well recognized as the most important arthropod vectors of disease-causing pathogens. This is because most species must feed on vertebrate blood as adult females to reproduce. In turn, consumption of multiple blood meals enables pathogen transmission between hosts while vector abundance influences transmission risks. Thus, approaches that disrupt pathogen transmission and/or reduce vector populations are both strategies for disease control. Mosquitoes host microbes in their digestive tract that collectively form a gut microbiota. This application is a renewal request to continue our work on the essential role of the gut microbiota in mosquito development. Our current award focuses on Aedes aegypti, which is a major vector of several human diseases. Our studies to date indicate that microbe- induced gut hypoxia functions as a growth signal, and that transduction of this signal in mosquito larvae requires hypoxia-induced transcription factors (HIFs). Results further indicate that HIF signaling activates several processes with essential roles in nutrient acquisition, growth and metabolism. The overall goal of this proposal is to unravel the molecular mechanisms that connect microbe-induced gut hypoxia and HIF signaling to the nutrients and signaling pathways that regulate growth. Proposed studies have the potential for transformative impacts on understanding the role of the gut microbiota in development of most if not all vector mosquito species. Proposed Specific Aims are to: 1. Identify HIF target genes in Ae. aegypti. 2. Characterize Ae. aegypti HIF-? isoforms. 3. Analyze the role of HIF signaling in lipogenesis and midgut growth. 4. Assess the role of the gut microbiota as nutrient source for mosquito development. Expected outcomes will identify molecular targets for disrupting mosquito development and factors that could improve mosquito rearing for control programs. Results will also guide understanding of how diet and the gut microbiota regulate growth of all mosquito species.

Public Health Relevance

Mosquitoes are the most important arthropod vectors of disease-causing pathogens. Proposed studies will provide functional insights into how the gut microbiota of mosquitoes mediates development. Results will identify processes that can be used to disrupt or promote mosquito growth for vector control.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI106892-06
Application #
9804977
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Costero-Saint Denis, Adriana
Project Start
2014-09-16
Project End
2024-08-31
Budget Start
2019-09-01
Budget End
2020-08-31
Support Year
6
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of Georgia
Department
Zoology
Type
Earth Sciences/Resources
DUNS #
004315578
City
Athens
State
GA
Country
United States
Zip Code
30602
Strand, Michael R (2018) Composition and functional roles of the gut microbiota in mosquitoes. Curr Opin Insect Sci 28:59-65
Valzania, Luca; Coon, Kerri L; Vogel, Kevin J et al. (2018) Hypoxia-induced transcription factor signaling is essential for larval growth of the mosquito Aedes aegypti. Proc Natl Acad Sci U S A 115:457-465
Valzania, Luca; Martinson, Vincent G; Harrison, Ruby E et al. (2018) Both living bacteria and eukaryotes in the mosquito gut promote growth of larvae. PLoS Negl Trop Dis 12:e0006638
McKinney, David A; Strand, Michael R; Brown, Mark R (2017) Evaluation of ecdysteroid antisera for a competitive enzyme immunoassay and extraction procedures for the measurement of mosquito ecdysteroids. Gen Comp Endocrinol 253:60-69
Vogel, Kevin J; Valzania, Luca; Coon, Kerri L et al. (2017) Transcriptome Sequencing Reveals Large-Scale Changes in Axenic Aedes aegypti Larvae. PLoS Negl Trop Dis 11:e0005273
Coon, Kerri L; Valzania, Luca; McKinney, David A et al. (2017) Bacteria-mediated hypoxia functions as a signal for mosquito development. Proc Natl Acad Sci U S A 114:E5362-E5369
Coon, Kerri L; Brown, Mark R; Strand, Michael R (2016) Gut bacteria differentially affect egg production in the anautogenous mosquito Aedes aegypti and facultatively autogenous mosquito Aedes atropalpus (Diptera: Culicidae). Parasit Vectors 9:375
Coon, Kerri L; Brown, Mark R; Strand, Michael R (2016) Mosquitoes host communities of bacteria that are essential for development but vary greatly between local habitats. Mol Ecol 25:5806-5826
McKinney, David A; Eum, Jai-Hoon; Dhara, Animesh et al. (2016) Calcium influx enhances neuropeptide activation of ecdysteroid hormone production by mosquito ovaries. Insect Biochem Mol Biol 70:160-9
Strand, M R; Brown, M R; Vogel, K J (2016) Mosquito Peptide Hormones: Diversity, Production, and Function. Adv In Insect Phys 51:145-188

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