ICTV Virus Taxonomy Profile: Megabirnaviridae

Area of Science:

• Virology
• Mycology

Background:

• Megabirnaviridae is a viral family characterized by non-enveloped, spherical particles.
• These viruses possess a bisegmented double-stranded RNA (dsRNA) genome, totaling 16.1 kbp.
• The family includes the genus Megabirnavirus, with Rosellinia necatrix megabirnavirus 1 as the exemplar species.

Purpose of the Study:

• To provide a comprehensive summary of the family Megabirnaviridae based on the ICTV Report.
• To detail the genomic and morphological characteristics of megabirnaviruses.
• To highlight the biological significance of Rosellinia necatrix megabirnavirus 1 in conferring hypovirulence.

Main Methods:

• Review and summarization of the International Committee on Taxonomy of Viruses (ICTV) report on Megabirnaviridae.
• Analysis of genomic data, including dsRNA genome segmentation and untranslated regions.
• Description of viral particle morphology, focusing on surface protrusions.

Main Results:

• Megabirnaviridae viruses are non-enveloped with dsRNA genomes (two linear segments, 7.2-8.9 kbp each).
• Megabirnaviruses feature large 5'-untranslated regions (1.6 kbp) and prominent surface protrusions.
• Rosellinia necatrix megabirnavirus 1 infects the white root rot fungus, inducing hypovirulence.

Conclusions:

• Megabirnaviridae represent a distinct viral family with unique genomic and structural features.
• The study provides an official classification and description of the family.
• Understanding megabirnaviruses, like Rosellinia necatrix megabirnavirus 1, is crucial for fungal disease management.