Distinct Host Gene Expression Patterns Induced by Covert Deformed Wing Virus Infections in Honeybees (Apis mellifera)

Area of Science:

• Virology
• Insect Pathology
• Molecular Biology

Background:

• Deformed Wing Virus (DWV) is a significant pathogen impacting honeybee (Apis mellifera) colonies worldwide.
• Overt DWV infections manifest with visible deformities and behavioral alterations, but covert infections are poorly understood.
• Understanding subclinical DWV infections is crucial for managing honeybee health and colony losses.

Purpose of the Study:

• To investigate the host transcriptional response to asymptomatic Deformed Wing Virus (DWV) infections in honeybees.
• To compare gene expression patterns between covertly and overtly infected honeybees.
• To identify potential molecular biomarkers for early detection of DWV.

Main Methods:

• Transcriptomic analysis of Apis mellifera anatoliaca worker bees from an experimental apiary.
• Assembly of the viral genome from asymptomatic colonies to identify novel DWV strains.
• Comparative gene expression analysis to identify differentially regulated genes.

Main Results:

• A novel DWV-A/DWV-B recombinant (DWV_Ord1) was identified in asymptomatic honeybee colonies.
• Covertly infected bees exhibited upregulation of genes related to venom production, cuticular integrity, and light perception.
• These transcriptional changes suggest a state of heightened defensive readiness in bees with low-level DWV infections.

Conclusions:

• Nonsymptomatic DWV infections induce distinct transcriptional profiles compared to symptomatic cases.
• Upregulated genes in covertly infected bees may serve as early biomarkers for DWV detection.
• These findings enhance our understanding of honeybee immune responses to viral pathogens.