Family: Filoviridae

Genus: Striavirus


Distinguishing features

Xīlǎng virus (XILV) is the only classified striavirus. Like oblaviruses and thamnoviruses, but unlike cuevaviruses, dianloviruses, orthoebolaviruses, orthomarburgviruses, and tapjoviruses, striaviruses infect fish. Notably, striavirus genomes contain nine gene overlaps, encode at least three proteins without obvious homologs in viruses of other filovirid genera, and do not encode ribonucleoprotein (RNP) complex-associated protein (VP24) (Shi et al., 2018).


Virions are unknown.

Nucleic acid

Virions are assumed to contain one or several copies of the linear negative-sense RNA genome that are encapsidated independently.


Striaviruses likely express at least ten proteins, of which six (nucleoprotein [NP], polymerase cofactor [VP35], transcriptional activator [VP30], the matrix protein [VP40], glycoprotein [GP1,2], and large protein [L]) are homologs of proteins expressed by cuevaviruses, dianloviruses, orthoebolaviruses, orthomarburgviruses, and tapjoviruses, five (NP, VP35, GP1,2, VP30, L) are homologs of proteins expressed by oblaviruses, and four (NP, VP35, GP1,2, and L) are homologs of proteins expressed by thamnoviruses (Hume and Mühlberger 2019, Hierweger et al., 2021). After VP40, the second most abundant structural protein in virions is assumed to be NP, which encapsidates the striavirus genome. The least abundant protein is assumed to be L, which mediates striavirus genome replication and transcription.

Genome organization and replication

The striavirus genome has the gene order 3′-NP-VP35-VP40-U1-GP-U2-VP30-U3-U4-L-5′ (Shi et al., 2018), with U denoting genes expressing proteins of unknown function (Figure 1.Striavirus). The undetermined extragenic sequences at the extreme 3′-end (leader) and 5′-end (trailer) of the genome are assumed to be conserved and partially complementary. Genes are flanked by unique conserved transcriptional initiation and termination (polyadenylation) sites (Hume and Mühlberger 2019). All striavirus genes overlap.

Striavirus genome
Figure 1. Striavirus. Schematic representation of striavirus genome organization, drawn to scale. GP, glycoprotein gene; L, large protein gene; NP, nucleoprotein gene; U1/2/3/4, genes encoding proteins of unknown function; VP30, transcriptional activator gene; VP35, polymerase co-factor gene. Wavy lines indicate incomplete genome ends.

The replication strategy of striaviruses remains to be studied.


Striaviruses were discovered in 2011 by high-throughput sequencing of samples taken from striated frogfish (antennariid Antennarius striatus (G. Shaw, 1794)) captured by fishing trawlers in the East China Sea (Shi et al., 2018).

Species demarcation criteria

The genus currently includes only a single species.