Natural invertebrate hosts of iridoviruses (Iridoviridae)

Abstract

Neotropical Entomology 37(6): 615-632 (2008) Hospederos Naturales de los Iridovirus de Invertebrados RESUMEN -Los virus iridiscentes de invertebrados (VIIs) son virus icosaedrales de ADN que infectan a invertebrados, principalmente insectos e isópodos terrestres en hábitats húmedos y acuáticos. Búsquedas extensivas de bases de datos resultaron en la identifi cación de 79 artículos científi cos, los cuales reportaron 108 especies de invertebrados infectados naturalmente por iridovirus. De estos, 103 (95%) fueron artrópodos y los otros fueron moluscos, un anélido y un nematodo. Nueve especies fueron de hábitats marinos. De las 99 especies no marinas, 49 fueron terrestres y 50 fueron acuáticas, especialmente los estadios acuáticos de dípteros (44 especies). La abundancia de infecciones en especies de Aedes, Ochlerotatus y Psorophora se contrasta marcadamente con la escasez de casos en especies de Anopheles, Culex y Culiseta. Reportes de infecciones de los isópodos terrestres son numerosos (19 especies), aunque la diversidad de los VII que los infectan es desconocida. Se han reportado infecciones por VIIs de todos los continentes, excepto Antártica, pero se notan pocos ejemplos de África, Asia y Latinoamérica. La mayoría de los artículos señala que las infecciones patentes son poco comunes, mientras que las infecciones enmascaradas (subletales) pueden ser comunes en algunas especies. La relación entre el tamaño de la partícula y el color iridiscente concuerda con la teoría óptica en casi todos los casos. Veinticuatro de los VIIs de insectos han sido caracterizados parcialmente y solo dos de éstos han sido secuenciados completamente. Demuestro que el ritmo de publicación sobre los VIIs ha disminuido en los últimos 15 años, señalo varias conclusiones y sugerencias de la lista de especies de huéspedes y presento algunas recomendaciones para la investigación futura con este grupo de patógenos.PALABRAS CLAVE: Abundancia, infección, huésped natural, tamaño de partícula, caracterización de virus ABSTRACT -Invertebrate iridescent viruses (IIVs) are icosahedral DNA viruses that infect invertebrates, mainly insects and terrestrial isopods, in damp and aquatic habitats. Exhaustive searches of databases resulted in the identifi cation of 79 articles reporting 108 invertebrate species naturally infected by confi rmed or putative iridoviruses. Of these, 103 (95%) were arthropods and the remainder were molluscs, an annelid worm and a nematode. Nine species were from marine habitats. Of the 99 non-marine species, 49 were from terrestrial habitats and 50 were aquatic, especially the aquatic stages of Diptera (44 species). The abundance of records from species of Aedes, Ochlerotatus and Psorophora contrasts markedly with a paucity of records from species of Anopheles, Culex and Culiseta. Records from terrestrial isopods are numerous (19 species), although the diversity of IIVs that infect them is mostly unstudied. IIV infections have been reported from every continent, except Antarctica, but there are few records from Africa, sout...

Comparative Metagenomics of Viral Assemblages Inhabiting Four Phyla of Marine Invertebrates

“…This would indicate that NPV's detected in the 2011 Hewson et al study were most likely from amphipod hosts. Iridoviruses have been found within insects, mollusks, crustacean, and cnidarians in previous studies (Williams, 2008;Weynberg et al, 2014), but were detected in Demasterias imbricata, P. helianthoides (second diseased sample from the Seattle Aquarium), E. troscheli (second diseased sample from Cates Park Reef), and GenomePlex-prepared P. chilensis samples from Chile. They may have enveloped or non-enveloped icosahedral capsids (depending on if they resulted from budding or release via lysis) and contain a linear genome of 140-303 kb that encodes a highly variable number of genes (Darai, 1989).…”

Genomic and Proteomic Analysis of Invertebrate Iridovirus Type 9

“…(Lepidoptera: Hepialidae) (9). The mechanism of transmission of this virus is unknown, though the presence of this virus in damp and cryptic habitats is consistent with many other IIV (40), and suggestions of vector transmission have been made, though not confirmed. Like most invertebrate iridoviruses, IIV-9 replicates in larvae of the greater wax moth Galleria mellonella upon injection, and heavily infected larvae display typical iridescence upon accumulation of paracrystalline arrays of virus particles within infected tissues (9).…”

Complete genome sequence of invertebrate iridovirus IIV22A, a variant of IIV22, isolated originally from a blackfly larva

“…The family Iridoviridae is currently organized into five genera: Chloriridovirus, Iridovirus, Lymphocystivirus, Megalocytivirus and Ranavirus. Members of the two first genera have a host range restricted to invertebrate species (arachnids, cephalopods, crustaceans, insects, mollusks, nematodes, and polychetes; for review, see [2]), whereas members of the three other infect only poikilothermic vertebrates (fishes, amphibians and reptiles). These viruses are members of the nucleoplasmic large DNA viruses (NLCDV) [3], now referred to as the Megavirale [4].…”