McKenna, Claire Helen (2017-05). Gene Expression in Lucilia sericata (Diptera: Calliphoridae) Larvae Exposed to Pseudomonas aeruginosa and Acinetobacter baumannii. Master's Thesis.
The green bottle fly (Lucilia sericata) larvae are amongst the first colonizers of carrion and are well studied for their impact in forensics, decomposition ecology, and medicine. The larvae of L. sericata are the only FDA approved species for maggot therapy and can be successful in wound debridement, disinfection, and contribute to wound healing and tissue regeneration. Because these larvae naturally colonize habitats with high microbial loads, it is not surprising that they have a large repertoire of antimicrobial peptides. In this study, 2nd instar L. sericata larvae were exposed to Gramnegative bacteria (Pseudomonas aeruginosa or Acinetobacter baumannii) and evaluated for differences in transcript abundance due to bacterial exposure identified through RNA-seq analysis. Differentially expressed genes were identified and characterized by analyzing RNA-seq data with traditional software analysis and gene ontology methodologies. Up-regulated and down-regulated genes included those associated with the recognition, signaling cascades, and effector molecule transcription of the insect immune response pathways. Differentially expressed transcripts also included some previously identified antimicrobial peptides. Other differentially expressed genes were uncharacterized and so functions were not attributed to these genes. The data produced in this study may contribute to future studies such as the potential identification of new antimicrobial peptides, genome editing or genetic engineering of Medical Maggots(TM), and transcriptome studies in L. sericata as well as other organisms.