Impacts of in Ovo Aflatoxin B1 on Domestic and Wild Turkey Transcriptomes

Contamination of corn and grains with aflatoxin B₁ (AFB₁) is a worldwide food safety and animal health issue linked to economic losses in agriculture.  Consumption of AFB₁ is hepatotoxic, carcinogenic and immunosuppressive; domestic turkeys (Meleagris gallopavo) are especially sensitive to its effects.  Eastern wild turkeys (M. gallopavo silvestris) are far less susceptible than their domestic counterparts due to their capability to detoxify AFB₁.  In ovo exposure to AFB₁ provides a model for controlled AFB₁ challenge and comparison of domestic and wild turkeys.  Utilizing RNA-sequencing (RNA-seq), the impact of AFB₁ on genome-wide expression in embryonic liver and spleen can be investigated.  Eggs were injected with 1 μg of AFB₁ or sham control and tissue samples were collected after a 1 or 5 day exposure period.  Libraries were sequenced on the Illumina HiSeq 2000 to produce approximately 10 M 100 bp paired-end reads per library.  Predicted transcripts were assembled in CLC Genomics Workbench using both de novo and short-read alignment pathways.  Differential expression analysis with DESeq will identify effects of AFB₁ exposure in wild and domestic embryonic tissue and examine the factors of exposure time and tissue type.  Comparing the transcriptome response to AFB₁ in wild and domestic turkeys can provide insight into changes during domestication and help elucidate ways to improve poultry resistance to AFB₁.