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Volume 50, Number 6, December 2017

RNA recombination in Hepatitis delta virus: Identification of a novel naturally occurring recombinant 


Chia-Chi Lin, Chi-Ching Lee, Siao-Han Lin, Po-Jung Huang, Hsin-Pai Li, Yu-Sun Chang, Petrus Tang, Mei Chao


 

Corresponding author:

Mei Chao, Corresponding authors. Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Number 259, Wenhua First Road, Guishan, 33302 Taoyuan, Taiwan. 



 

Background and purpose: 

Hepatitis delta virus (HDV) is the only animal RNA virus that has an unbranched rod-like genome with ribozyme activity. It replicates in the nucleus by host RNA polymerase via a rolling circle mechanism. Similar to many RNA viruses encoding their own RNA-dependent RNA polymerases, homologous recombination of HDV occurs in mixed-genotype infections and in cultured cells cotransfected with two HDV sequences, as demonstrated by molecular analyses. 



 

Methods:

Among 237 published complete genomic sequences, 34 sequences were reported from the small and isolated Miyako Island, Japan, and belonged to the Asia-specific genotypes, HDV-2 and HDV-4 (the majority of them belonged to the known Miyako Island-specific subgroup, HDV-4M). We investigated the presence of naturally occurring HDV recombinant in Miyako Island using phylogenetic and recombination analyses. 



 

Results:

We identified a two-switch HDV-4/4M intersubtype recombinant with an unbranched rod-like RNA genome. 



 

Conclusion:

Our data suggest that RNA recombination plays an important role in the rapid evolution of HDV, allowing the production of new HDV strains with correct genomic structures. 



 

Key words:

hepatitis delta virus, RNA recombination