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The origins and ongoing evolution of viruses
R W Hendrix1, J G Lawrence, G F Hatfull
1Pittsburgh Bacteriophage Institute, PA 15260, USA. rhx@pitt.edu
Trends in Microbiology
|December 21, 2000
Summary
Double strand DNA tailed bacteriophages evolve through gene reassortment and acquiring new genes called morons. This suggests viruses co-evolved with hosts, rather than solely from cells.
Area of Science:
- Virology
- Molecular Biology
- Evolutionary Biology
Background:
- Double strand DNA tailed bacteriophages are ubiquitous viruses with complex genomes.
- Understanding their evolutionary mechanisms is key to comprehending viral diversity and adaptation.
Purpose of the Study:
- To investigate the evolutionary processes driving the diversification of double strand DNA tailed bacteriophages.
- To propose a model for early virus evolution based on observed genetic mechanisms.
Main Methods:
- Genome-wide analyses of double strand DNA tailed bacteriophage sequences.
- Identification and characterization of mobile genetic elements within phage genomes.
Main Results:
- Phage evolution is characterized by recombinational reassortment of existing genes.
- Acquisition of novel genes, termed morons, contributes significantly to phage adaptation.
- Morons represent simple genetic elements facilitating rapid evolutionary changes.
Conclusions:
- The evolution of double strand DNA tailed bacteriophages is a dynamic process involving both internal gene shuffling and external gene acquisition.
- These evolutionary strategies suggest a model where viruses are active partners in co-evolution with their hosts, rather than passive derivatives of cellular life.
- This perspective reframes our understanding of early viral evolution and host-virus interactions.
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