Small RNA populations for two unrelated viruses exhibit different biases in strand polarity and proximity to terminal sequences in the insect host Homalodisca vitripennis

Next generation sequence analyses were used to assess virus-derived small RNA (vsRNA) profiles for Homalodisca coagulata virus-1 (HoCV-1), family Dicistroviridae, and Homalodisca vitripennis reovirus (HoVRV), family Reoviridae, from virus-infected H. vitripennis, the glassy-winged sharpshooter. The vsRNA reads were mapped against the monopartite genome of HoCV-1 and all 12 genome segments of HoVRV, and 21 nt vsRNAs were most common. However, strikingly contrasting patterns for the HoCV-1 and HoVRV genomic RNAs were observed. The majority of HoCV-1 vsRNAs mapped to the genomic positive-strand RNA and, although minor hotspots were observed, vsRNAs mapped across the entire genomic RNA. In contrast, HoVRV vsRNAs mapped to both positive and negative-sense strands for all genome segments, but different genomic segments showed distinct hotspots. The HoVRV vsRNAs were more common for 5' and 3' regions of HoVRV regions of all segments. These data suggest that taxonomically different viruses in the same host offer different targets for RNA-antiviral defense. (C) 2013 Elsevier Inc. All rights reserved.