Dicistroviridae

Definition

A family of positive-sense single-stranded RNA viruses in the order Picornavirales that infect invertebrates, particularly insects and other arthropods. Members are characterized by a bicistronic genome organization with two open reading frames separated by an intergenic region containing an internal ribosome entry site (IGR-IRES), a feature reflected in the family name (from Greek 'di-' meaning two and 'cistron' referring to a coding sequence). The family comprises three genera—Aparavirus, Cripavirus, and Triatovirus—with 16 recognized species. These viruses range from commensal to highly pathogenic: some strains increase host reproductive potential, while others cause paralysis and mortality.

Etymology

From Greek 'di-' (two) + 'cistron' (coding sequence, referring to the bicistronic genome) + '-viridae' (family suffix for viruses)

Example

Drosophila C virus (genus Cripavirus) is a well-studied dicistrovirus that causes pathology in fruit flies only at high titers, whereas Cricket paralysis virus (also Cripavirus) is extremely virulent, inducing paralysis and death in crickets and other orthopterans; both are used as models to study IRES-mediated translation and host–virus coevolution in insects.

Related Terms

• Picornavirales
• Cripavirus
• Aparavirus
• Triatovirus
• DCV
• CrPV
• invertebrate virus
• RNA virus
• IGR-IRES
• host–pathogen interaction
• insect pathology

Usage Notes

Dicistroviridae is treated as a plural proper noun in formal taxonomic usage (the family name), though it refers to a single taxonomic family. The distinguishing bicistronic genome architecture separates this family from other picorna-like viruses. Many dicistroviruses are detected as persistent, asymptomatic infections in natural insect populations, complicating their identification as primary disease agents. The family name is sometimes misspelled 'Dicistroviridae' without the second 'i', but the accepted ICTV spelling retains both vowels. Research applications include using dicistrovirus IGR-IRES elements as tools for bicistronic expression in heterologous systems.