Khalifa, M.E.; MacDiarmid, R.M. Molecular Characterization of Two Totiviruses from the Commensal Yeast Geotrichum candidum. Viruses2023, 15, 2150.
Khalifa, M.E.; MacDiarmid, R.M. Molecular Characterization of Two Totiviruses from the Commensal Yeast Geotrichum candidum. Viruses 2023, 15, 2150.
Khalifa, M.E.; MacDiarmid, R.M. Molecular Characterization of Two Totiviruses from the Commensal Yeast Geotrichum candidum. Viruses2023, 15, 2150.
Khalifa, M.E.; MacDiarmid, R.M. Molecular Characterization of Two Totiviruses from the Commensal Yeast Geotrichum candidum. Viruses 2023, 15, 2150.
Abstract
Mycoviruses are widespread across the major taxa of fungi including yeasts. Mycoviruses in the yeast fungus Geotrichum candidum are not well studied with three G. candidum-associated viral species characterized to date, all of which belong to the Totiviridae genus Totivirus. In this study, we report the molecular characteristics of another two totiviruses co-infecting isolate Gc6 of G. candidum. The two totiviruses were tentatively named Geotrichum candidum totivirus 2 (GcTV2-Gc6) and GcTV4-Gc6). Both viruses have typical genome organization of totiviruses comprising two ORFs encoding capsid protein (CP) and RNA-dependent RNA polymerase (RdRp) at the N and C termini, respectively. Genomes of GcTV2-Gc6 and GcTV4-Gc6 are 4592 and 4530 bp long, respectively. Both viruses contain the -1 frameshifting elements and their proteins could be expressed as a single fusion protein. GcTV2-Gc6 is closely related to a totivirus isolated from the same host whereas GcTV4-Gc6 is related to insect-associated totiviruses. The phylogenetic analysis indicated that GcTV2-Gc6 and GcTV4-Gc6 belong to two different sister clades, I-A and I-B, respectively. It is interesting that all viruses identified from G. candidum belong to the genus Totivirus. It is possible that the RNA interference (RNAi) mechanism is not active to suppress totivirus accumulation in isolate Gc6.
Keywords
mycoviruses; dsRNA; Totivirus; Geotrichum; high throughput sequencing; siRNA; RNA interference
Subject
Biology and Life Sciences, Virology
Copyright:
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