Diverse circular replication-associated protein encoding viruses circulating in invertebrates within a lake ecosystem

Area of Science:

• Environmental virology
• Metagenomics
• Ecosystem dynamics

Background:

• Next-generation sequencing has revolutionized microorganism identification, particularly in environmental virology.
• Previous studies identified numerous single-stranded DNA (ssDNA) viruses but explored feeding relationships less.
• Understanding viral sharing through ecological interactions is crucial for ecosystem health.

Purpose of the Study:

• To identify and classify circular DNA viruses in a New Zealand freshwater lake ecosystem.
• To investigate the diversity and distribution of these viruses in aquatic organisms and environmental samples.
• To explore potential correlations between viral assemblages and host feeding relationships.

Main Methods:

• Utilized next-generation sequencing for viral metagenome analysis.
• Recovered and analyzed 169 circular molecules, including 160 CRESS DNA molecules.
• Tentatively classified viral sequences into novel and known species based on genetic similarity.

Main Results:

• Identified 169 circular molecules, classifying them into 51 putatively novel and five known viral species.
• Detected CRESS DNA viruses in molluscs, insect larvae, lake water, and benthic sediments.
• Observed extensive diversity among recovered CRESS DNA molecules, with one species related to Tombusviridae.

Conclusions:

• This study significantly expands the known diversity of circular DNA viruses in freshwater ecosystems.
• Found associations between CRESS DNA viruses and specific aquatic organisms and environmental compartments.
• Did not find significant correlations between viral communities and host feeding relationships, suggesting complex transmission routes.