Host Range Breadth Correlates with Genic Diversity in Honeybee Phages

Area of Science:

• Microbiology
• Evolutionary Biology
• Genomics

Background:

• Bacteriophages (phages) evolve rapidly through mutation and horizontal gene transfer to overcome microbial host defenses.
• Understanding phage genomic evolution within natural microbial communities, particularly their host range, remains challenging.

Purpose of the Study:

• To investigate the interplay between phage ecology and genome evolution within honeybee worker microbiomes.
• To infer evolutionary pressures acting on phage genomes by correlating host range with genomic variation.

Main Methods:

• Combined in vivo phage host range measurements with genome evolution analysis in honeybee microbiomes.
• Utilized HiC-resolved metagenomics to study phage communities in the honeybee gut.
• Estimated genic diversity and identified loci under diversifying selection.

Main Results:

• Near-identical phage genomes co-occurred across honeybee colonies, displaying significant gene module variation despite a conserved core genome.
• Genic diversity estimates deviated from neutral models, indicating loci under diversifying selection.
• Honeybee gut phage communities exhibited wide host range variation, differing in host number and phylogenetic distance across individuals.
• Genetic variation positively correlated with phage host range, with selection targets differing between broad and narrow host range phages.

Conclusions:

• Honeybee-associated phages display substantial host range variation within host-associated microbial communities.
• This host range variation significantly influences the rates and patterns of phage evolution.