# Assessing the physiological roles of distinct insulin-like peptides in the mosquito Aedes aegypti

> **NIH NIH R21** · UNIVERSITY OF ARIZONA · 2020 · $230,250

## Abstract

Abstract
The insulin/insulin growth factor signaling (IIS) cascade is one of the most important signaling pathways in
insects. IIS in insects regulate everything from development and growth during the immature stages, to
reproduction and longevity in adult insects, to metabolism and innate immunity during all stages. While insects
typically encode multiple insulin-like peptides (ILPs), these hormones appear to largely activate the IIS
cascade via a single insulin receptor. This raises a fundamental question as to why multiple ILPs are
necessary. They may be redundant to ensure that mutations in this critical signaling pathway are compensated
for. They may act in concert to fine tune the physiologies regulated by this cascade. Or they may
independently control distinct physiological processes. To explore these possibilities, we will knock-out
individual ILPs in the mosquito Aedes aegypti using the CRISPR/Cas9 system. Ae. aegypti encodes eight
different ILPs and we will knock-out at least three of the most intriguing ones; 1) AaegILP2, an ortholog of
Drosophila DILP2, which has been implicated in regulating lifespan, reproduction, and development, 2)
AaegILP6, the only putative insulin growth factor identified in mosquitoes to date, and 3) AaegILP3, which has
been shown through peptide injections to control metabolism and reproduction. For these three AaegILP
knock-outs lines, and any others that time and resources allow for, we will conduct expression assays in
various tissues, various developmental periods and following various physiological events. We will also assess
the impact of the individual AaegILP knock-outs on the following physiologies: growth and development,
lifespan, metabolism, lifetime fecundity, and innate immunity. By the end of this project we will have elucidated
the basic biological roles of three or more AaegILPs, broadening our understanding of key factors regulating
vectorial capacity in this important arboviral vector.

## Key facts

- **NIH application ID:** 9868266
- **Project number:** 5R21AI144455-02
- **Recipient organization:** UNIVERSITY OF ARIZONA
- **Principal Investigator:** Michael Allen Riehle
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $230,250
- **Award type:** 5
- **Project period:** 2019-02-08 → 2023-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9868266

## Citation

> US National Institutes of Health, RePORTER application 9868266, Assessing the physiological roles of distinct insulin-like peptides in the mosquito Aedes aegypti (5R21AI144455-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9868266. Licensed CC0.

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