Seminars

RNA interference (RNAi) is mediated by 18-30nt small RNAs with pervasive roles in negative regulation of gene expression and defense against invasive genetic elements (i.e. viruses and transposons). Manipulation of this process has led to genetic technologies in many eukaryotes; however, gene silencing varies dramatically by species. This is particularly the case in invertebrates where small RNAs are key to rapidly evolving genome defense mechanisms. RNAi has been explored in the most detail in model organisms that represent clades such as mammals, flies, and nematodes. This leaves several major groups of animals relatively unexplored–basal arthropods (hemimetabolous insects & chelicerates) and all lophotrochozoans (mollusks & annelids). Fortunately, small RNA sequencing yields data that can be used to not only determine expression but also processing. Our work leverages this to discover novel small RNA biology in organisms that may be expected to have divergent function due to their branch in animal phylogeny.

The seminar will highlight my group’s exploration of pathways in: D. farinae (dust mites), T. Urtica (two-spot spider mites), B. tabaci (whitefly), C. teleta (marine annelid), and C. virginica (eastern Oyster). By conducting annotations and examining developmental and tissue expression multiple exotic behaviors were found in small RNAi pathways. This includes dramatic events such as loss of major types and switching roles. These basic insights shed light on animal genome evolution as well as guide development of gene silencing approaches in disparate clades.