GSE185938
Exploration of RNA-Seq data to identify a potential pathogen of the leaf-mining moth, Stomphastis sp. (Lepidoptera: Gracillariidae)
The leaf-mining moth (Stomphastis sp.) was imported to Australia as a potential biological control agent of a weed, Bellyache bush (Jatropha gossypiifolia). The insect colony has been maintained in the quarantine facility for over eight years. Recently, significant mortality was observed in the population. The larvae demonstrated swollen intersegments with a fragile integument. The infected larvae are cloudy muted green or yellowish whereas a healthy late instar larva is a vivid green. They slowly dehydrate and eventually die and when death occurs, the larval body becomes rubbery and turns to black. We used next generation sequencing approach to identify the cause of mortality in the population. Total RNA was extracted from 20 larvae in two cohorts with and without apparent symptoms of disease for deep sequencing on NovaSeq platform after eukaryote ribosomal RNA depletion. We identified several non-insect sequences belonging to viruses, bacteria and fungi but none of those showed significant abundance or enrichment in the infected dataset. The sequences related to a unicellular yeast, Saccharomyces cerevisiae, are among the highly expressed non-insect contigs and more than 5% of reads in both libraries mapped to the genome of this opportunistic microorganism. Overall design: Total RNA was extracted from 20 Stomphastis larvae in two cohorts with and without apparent symptoms of unknown disease in the laboratory population.