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Arbovirus Infections As Screening Tools for the Identification of Viral Immunomodulators and Host Antiviral Factors
Published on: September 13, 2018
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Jawless vertebrates do not escape retrovirus infection
Lingyu Chu1, Fang Su1, Guan-Zhu Han1
1Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, 210023, China.
Virology
|May 6, 2023
Summary
Researchers discovered novel endogenous retroviruses (ERVs) in hagfish, expanding our understanding of retroviral evolution beyond jawed vertebrates. These ancient ERVs offer insights into early retrovirus history.
Area of Science:
- Evolutionary biology
- Genomics
- Virology
Background:
- Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections integrated into host genomes.
- ERVs serve as molecular fossils, crucial for tracing the deep evolutionary history of retroviruses.
- While ERVs are well-studied in jawed vertebrates, their diversity and evolution in jawless vertebrates remain largely unknown.
Purpose of the Study:
- To investigate the presence and diversity of ERVs in jawless vertebrates.
- To characterize a newly discovered ERV lineage in the hagfish *Eptatretus burgeri*.
- To understand the evolutionary origins and dynamics of these ERVs.
Main Methods:
- Genome sequencing and analysis of *Eptatretus burgeri*.
- Phylogenetic analyses to determine the evolutionary relationships of novel ERVs.
- Evolutionary dynamics and transposition activity analyses.
Main Results:
- Discovery of a novel ERV lineage, named EbuERVs, in the hagfish genome.
- Phylogenetic analysis indicates EbuERVs belong to epsilon-retroviruses, possibly originating from gene transfer from jawed vertebrates.
- Estimated invasion time in the hagfish genome is tens of millions of years ago, with a past proliferation peak and current inactivity in transposition.
- Some EbuERVs are transcribed in embryos and may function as long non-coding RNAs (lncRNAs).
Conclusions:
- This study expands the known distribution of endogenous retroviruses from jawed to jawless vertebrates.
- The findings provide new insights into the ancient history and evolution of retroviruses.
- EbuERVs represent a valuable resource for studying vertebrate evolution and retroviral paleogenomics.
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