Related Experiment Video
Updated: May 28, 2026
09:01
Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi
Published on: September 28, 2022
Narrowed host ranges do not constrain future host range expansion in RNA phage Φ6
Taylor P Andrews1, Abbey Isaac2, Siobain Duffy3
1Microbial Biology Graduate Program, Rutgers University, New Brunswick, New Jersey, USA.
Journal of Virology
|May 27, 2026
Summary
RNA viruses that specialize on one host can readily regain broad host ranges by reversing mutations or acquiring new ones. This adaptability is crucial for understanding viral evolution and host shifts in nature.
Area of Science:
- Evolutionary Biology
- Virology
- Genetics
Background:
- RNA viruses frequently shift hosts, sometimes specializing on a new host at the expense of others.
- The impact of host specialization on a virus's future evolutionary capacity is not well understood.
Purpose of the Study:
- To investigate the evolutionary potential of specialized RNA viruses.
- To understand the mechanisms by which viruses re-expand their host range after specialization.
Main Methods:
- Used previously evolved specialized strains of bacteriophage Φ6.
- Challenged these specialized strains to adapt to ancestral and other hosts.
- Identified resulting mutations and analyzed host range re-expansion.
Main Results:
- Specialized Φ6 strains readily re-expanded their host ranges at rates comparable to emergence events.
- Host range re-expansion occurred through reversal of previous mutations or acquisition of secondary/parallel mutations.
- No significant constraint from mutational backgrounds due to epistasis was observed.
Conclusions:
- RNA viruses possess significant potential for host range re-expansion following specialization.
- Mechanisms include both reversion of prior adaptations and novel mutations.
- Findings are relevant to understanding recurring host shifts and spillback events in natural viral populations.
Related Concept Videos
01:26DNA Bacteriophages
Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
00:43Lysogenic Cycle of Bacteriophages
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
01:29Viruses of Archaea
Archaeal viruses play a crucial role in the ecosystems of extremophilic archaea, particularly those belonging to the phyla Euryarchaeota and Crenarchaeota. By shaping host evolution and facilitating gene transfer, these viruses influence microbial communities and contribute to genetic diversity in extreme environments. The archaea they infect thrive in acidic hot springs and hydrothermal vents characterized by high temperatures and low pH. Archaeal viruses exhibit remarkable structural...
01:29Viruses with RNA Genomes
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
01:26Size and Structure of Viral Genomes
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
01:30Lytic Cycle of Bacteriophages
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the lytic replication...