# Mechanisms and Evolutionary Consequences of a Reproduction-Immunity Tradeoff

> **NIH NIH R01** · CORNELL UNIVERSITY · 2020 · $511,558

## Abstract

PROJECT SUMMARY
All organisms must simultaneously balance multiple competing demands on their energetic and
physiological resources. This can result in conflict among traits, driving physiological and evolutionary
tradeoffs. Defense against infection and reproductive capacity are each under strong natural selection
as important contributors to evolutionary fitness, both are energetically demanding, and tradeoffs
between the two are nearly universal in plants and animals, including those with public health
importance. Yet despite their ubiquity and importance, surprisingly little is known about the mechanistic
basis for reproduction-immunity tradeoffs. This shortcoming in knowledge limits inference about the
evolutionary process and applies practical limitations on the capacity for interventions to control insect
pests in agricultural or public health contexts. The proposed project will use the tractable model insect
Drosophila melanogaster to determine mechanisms by which reproductive investment constrains
immune performance, exploring the evolutionary implications of the tradeoff and providing rare
understanding of how life history tradeoffs arise and are maintained. The project will test of the
hormonal theory of pleiotropy, which posits that endocrine signaling can act as a master regulator to
shape life history tradeoffs, with a focus on insect Juvenile Hormone (JH). Initial experiments will
determine the temporal kinetics of JH signaling in response to mating and the quantitative relationship
between JH signal intensity and degree of immune suppression. Subsequent experiments will
determine the mechanisms by which JH suppresses immunity, seeking to identify novel regulatory
processes, testing a hypothesis that the tradeoff can arise through strain on cellular infrastructure, and
determining whether immunosuppression can be decoupled from reproductive investment. Additional
experiments will test whether naturally occurring genetic variation in JH signaling determines natural
phenotypic variability in the magnitude of the reproduction-immunity tradeoff and whether energetic
investment required for reproductive output directly limits the quality of immune defense. The data
obtained will comprise an in-depth study of the focal system and will reveal principles that can be
generalized across diverse systems.

## Key facts

- **NIH application ID:** 9936366
- **Project number:** 5R01AI141385-02
- **Recipient organization:** CORNELL UNIVERSITY
- **Principal Investigator:** Brian Lazzaro
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $511,558
- **Award type:** 5
- **Project period:** 2019-06-01 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9936366

## Citation

> US National Institutes of Health, RePORTER application 9936366, Mechanisms and Evolutionary Consequences of a Reproduction-Immunity Tradeoff (5R01AI141385-02). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/9936366. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*