Related Experiment Video
Updated: Jun 26, 2026

Generation of Escape Variants of Neutralizing Influenza Virus Monoclonal Antibodies
Published on: August 29, 2017
HA thermostability mutations S84F, G167N, and D168N potentiate H9N2 virus transmission in a warming environment
Xinyi Pei1,2,3, Wei Chen1,2,3, Hanyan Xiao1,2,3
1National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China.
Abstract:
Avian influenza A (H9N2) viruses are widespread in poultry and occasionally infect mammals, contributing genes to other emerging strains. The factors that allow these viruses to withstand higher temperatures are not well understood. In this study, we used high-temperature selection and deep mutational scanning of a saturated H9N2 hemagglutinin (HA) mutant library. We identified three HA mutations, S84F, G167N, and D168N, that increase viral thermostability. Viruses with these mutations survived better at elevated temperatures. In transmission experiments with chickens, the S84F mutation allowed waterborne spread at a temperature that blocked transmission of the wild-type virus. The combination of all three mutations was associated with evidence of airborne transmission in one of two experimental replicates. These results link HA thermostability to environmental persistence and transmission potential under thermal stress, which may affect the ecology of H9N2 viruses.
Related Concept Videos
Viral Mutations
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Mutations in Microorganisms

