A dsRNA virus with filamentous viral particles

Area of Science:

• Virology
• Mycology
• Molecular Biology

Background:

• Viruses with double-stranded RNA (dsRNA) genomes typically exhibit isometric particles or lack capsids.
• The diversity of viral structures and genome organizations remains an active area of research.

Purpose of the Study:

• To characterize a novel filamentous dsRNA virus, Colletotrichum camelliae filamentous virus 1 (CcFV-1), isolated from a fungal pathogen.
• To investigate the genome, particle morphology, and phylogenetic relationships of CcFV-1.

Main Methods:

• Isolation and characterization of CcFV-1 from Colletotrichum camelliae.
• Genome sequencing and analysis of dsRNA segments.
• Phylogenetic analysis to determine evolutionary relationships.
• Inoculation studies with naked dsRNA to assess infectivity and particle formation.

Main Results:

• Identification of CcFV-1, an eight-segmented dsRNA virus forming filamentous particles.
• The genome encodes 10 open reading frames, including RNA-dependent RNA polymerase and capsid protein.
• Naked CcFV-1 dsRNA is infectious and induces particle formation in vivo.
• CcFV-1 shows phylogenetic relatedness to other mycoviruses but differs in morphology and genome segmentation.

Conclusions:

• CcFV-1 represents a significant addition to the known virosphere diversity due to its unique filamentous structure.
• The virus may represent an evolutionary intermediate or a distinct encapsidating strategy.
• Findings contribute to understanding the architecture and diversity of dsRNA viruses and their hosts.