# The basis of Influenza A virus strain-dependent reassortment potential

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2024 · $416,635

## Abstract

Abstract
DESCRIPTION: Influenza viruses can exchange genome segments and generate new
viruses when they infect the same cell, a process called reassortment. These new viruses
can worsen seasonal flu epidemics or spark global pandemics. We recently found that
patterns of reassortment show strong strain-dependence, and do not necessarily track
similarity between coinfecting strains or their subtype (H1N1 or H3N2). The specific
factors underlying this strain dependence remain unclear. The role of protein
incompatibilities in restricting segment exchange was thought to be associated with
different subtypes. However, experimental tests of the role of subtype in promoting or
restricting reassortment remain very limited, and the specific protein incompatibilities
(antigenic versus polymerase complex) that are most important in shaping reassortment
remain unknown. Using our high-throughput tools, we propose to uncover the basis of
strain dependent reassortment potential. First, we will quantify reassortment patterns
within and between co-circulating human influenza strains of both subtypes and
measure differences in entry and coinfection. Second, we will use mutants to test the
effect of antigenic versus polymerase complex segments in driving reassortment
potential. Finally, we will examine whether post-reassortment mutations can
compensate fitness in strains arising from between-subtype reassortment and their
fitness in different host cell types. Collectively these aims will provide basic insight into
the factors affecting strain dependence in reassortment potential and provide actionable
data to refocus surveillance and pandemic preparedness efforts.

## Key facts

- **NIH application ID:** 10777914
- **Project number:** 1R01AI179873-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** Samuel L Diaz
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $416,635
- **Award type:** 1
- **Project period:** 2024-02-14 → 2029-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10777914

## Citation

> US National Institutes of Health, RePORTER application 10777914, The basis of Influenza A virus strain-dependent reassortment potential (1R01AI179873-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10777914. Licensed CC0.

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