Project description:The 791spin is the spinosad-selected strain derived from 791a, a laboratory strain derived from a multi-resistant field-collected sample of houseflies. The 791a strain proved highly resistant to pyrethroids and some anticholinesterases and showed some resistance to the chitin synthesis-disrupting larvicides.In order to understand the evolution of insecticide resistance, de novo assembly of a spinosad resistant housefly strain 791spin using 454 technology was initiated Transcriptome analysis of insecticide resistant housefly strain compared to susceptible strain
Project description:Hytrosaviridae family members replicate in the salivary glands (SGs) of their adult dipteran hosts and are transmitted to uninfected hosts via saliva during feeding. Despite inducing similar gross symptoms (SG hypertrophy; SGH), hytrosaviruses (SGHVs) have distinct pathobiologies, including sex-ratio distortions in tsetse flies and refusal of infected housefly females to copulate. Via unknown mechanism(s), SGHV replication in other tissues results in reduced fecundity in tsetse flies and total shutdown of vitellogenesis and sterility in housefly females. We hypothesized that vitellogenesis shutdown is caused by virus-induced modulation of hormonal titers. Here, we used RNA-Seq to investigate virus-induced modulation of host genes/pathways in healthy and virus-infected houseflies, and we validated expression of the most significantly modulated genes (n=23) by RT-qPCR. We also evaluated the levels and activities of hemolymph antimicrobial peptides (AMPs), levels of endogenous sesquiterpenoids, and impacts of exogenous hormones on ovarian development in viremic females. Of the 973 housefly unigenes that were significantly modulated (padj ≤ 0.01; log2FC ≤ or ≥ 2.0 ), 446 and 527 genes were downregulated and upregulated, respectively. While the most downregulated genes were related to reproduction (embryogenesis/oogenesis), the repertoire of upregulated genes was overrepresented by genes related to non-self recognition, ubiquitin-protease system, cytoskeletal traffic, cellular proliferation, development and movement, and snRNA processing. Overall, MdSGHV induced upregulation of components of the siRNA, innate antimicrobial immune, and autophagy pathways. MdSGHV reduced hemolymph sesquiterpenoids and completely shut down egg development in viremic females. However, the hormonal rescue of vitellogenesis did not result in egg production. The mechanism underlying MdSGHV-induced sterility has yet to be resolved.
Project description:The 791spin is the spinosad-selected strain derived from 791a, a laboratory strain derived from a multi-resistant field-collected sample of houseflies. The 791a strain proved highly resistant to pyrethroids and some anticholinesterases and showed some resistance to the chitin synthesis-disrupting larvicides.In order to understand the evolution of insecticide resistance, de novo assembly of a spinosad resistant housefly strain 791spin using 454 technology was initiated
