Gene Expression and Immune Response
McGrath, L. et al. "Antimicrobial peptide gene expression in Atlantic salmon (Salmo salar) seven days post-challenge with Neoparamoeba perurans." Developmental & Comparative Immunology (2022)
Objective: explore the role of antimicrobial peptides β-defensins and cathelicidins in N. perurans, which causes amoebic gill disease (AGD)
Utilization of Standard BioTools™ products: • Biomark™ HD system
• 48.48 Dynamic Array™ IFCs Conclusions: • Biomark HD shows β-defensins-3 and -4 and cathelicidin-2 were upregulated in gills of parasite-challenged salmon
• Indicate potential novel roles in innate immune responses to N. perurans
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SALMON CASE STUDY
Objective: The objective of this study was to measure gene expression levels of Hemocyte immune response genes when exposed to White Spot Syndrome Virus (WSSV) and Fusarium solani (fungal) in order to understand the molecular mechanisms driving shrimp-pathogen interactions to develop strategies to control disease outbreaks in shrimp production systems with L. vannamei. Utilization of Standard BioTools products: Biomark System NanoFlex 4-IFC Controller 96.96 dynamic arrays Real-Time PCR Analysis Software Conclusions: Genes that were monitored showed up regulation and down regulation over the time course study. Results reported can serve as immunomarkers for mortality events and could help reduce the loss in shrimp production systems
Results
• In infected salmon, β-defensin and cathelicidin expression was upregulated in the gill in response to early phase of parasitic infection, before clinical presentation was observed • Upregulation not observed in infected intestine and swim bladder, suggesting there is just a localized immune response in the gill at early stages of infection • β-defensin and cathelicidin expression found in healthy swim bladder for the first time
Conclusions
• Atlantic salmon AMP genes play a novel role in early asymptomatic innate immune responses to the parasite N. perurans
• β-defensin and cathelicidin expression confirmed in both healthy and infected Atlantic salmon
• Swim bladder (whose ancillary functions are largely unexplored) may have a novel immune role
Results and conclusions
Methods
• Total RNA was extracted from swim bladder (n=12), whole intestine (n=12) and whole gill (n=12) in control and infected salmon
• Standard BioTools workflows for reverse transcription, preamplification and data analysis were followed.
• Data was collected using the 48.48 GE IFC on Biomark HD
• Housekeeping genes elongation factor 1αa (EF1αa) and elongation factor 1αb (EF1αb) were selected as they are stable across a range of organs in Atlantic salmon
Background
• AGD is an infection of Atlantic salmon caused by N. perurans, and is a significant contributing factor to fish mortality • Antimicrobial peptides (AMP) β-defensins and cathelicidins, mediators of early immune response, have not yet been evaluated in relation to AGD • To assess the functional role that these genes play in local and systemic responses to infection, the authors measured gene expression in swim bladder, gill and intestine from healthy and infected salmon
