Viral discovery and diversity in trypanosomatid protozoa with a focus on relatives of the human parasite Leishmania.

摘要: Knowledge of viral diversity is expanding greatly, but many lineages remain underexplored. We surveyed RNA viruses in 52 cultured monoxenous relatives the human parasite Leishmania (Crithidia and Leptomonas), as well plant-infecting Phytomonas. Leptomonas pyrrhocoris was a hotbed for discovery, carrying virus (Leptomonas ostravirus 1) with highly divergent RNA-dependent polymerase missed by conventional BLAST searches, an emergent clade tombus-like viruses, example endogenization. A deep-branching trypanosomatid narnaviruses found, notable seymouri bearing Narna-like 1 (LepseyNLV1) have been reported cultures recovered from patients visceral leishmaniasis. lineage showing strong affinities to bunyaviruses termed “Leishbunyavirus” (LBV) judged sufficiently distinct warrant assignment within proposed family “Leishbunyaviridae.” Numerous were found insect metatranscriptomic surveys, which likely arise microbiota. Despite extensive sampling we no totivirus Leishmaniavirus (LRV1/2), implying that it acquired at about same time became able parasitize vertebrates. As over quarter isolates tested, more are be >600 unsurveyed species. Viral loss occasionally observed culture, providing potentially isogenic virus-free lines enabling studies probing biological role viruses. These data shed important insights on emergence relevant disease.