Novel insights into the insect trancriptome response to a natural DNA virus.
BACKGROUND
Little is known about invertebrate responses to DNA viruses. Here, we infect a commercially important pest moth species Plodia interpunctella with its naturally infecting DNA virus. We sequenced, assembled and annotated the complete transcriptome of the moth, and a partial transcriptome of the virus. We then tested for differential gene expression between moths that were exposed to the virus and controls.


RESULTS
We found 51 genes that were differentially expressed in moths exposed to a DNA baculovirus compared to controls. Gene set enrichment analysis revealed that cuticle proteins were significantly overrepresented in this group of genes. Interestingly, 6 of the 7 differentially expressed cuticle proteins were downregulated, suggesting that baculoviruses are able to manipulate its host's response. In fact, an additional 29 of the 51 genes were also downregulated in exposed compared with control animals, including a gram-negative binding protein. In contrast, genes involved in transposable element movement were upregulated after infection.


CONCLUSIONS
We present the first experiment to measure genome-wide gene expression in an insect after infection with a natural DNA virus. Our results indicate that cuticle proteins might be key genes underpinning the response to DNA viruses. Furthermore, the large proportion of genes that were downregulated after viral exposure suggests that this virus is actively manipulating the insect immune response. Finally, it appears that transposable element activity might increase during viral invasion. Combined, these results provide much needed host candidate genes that respond to DNA viral invaders.
Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories University of Edinburgh, Edinburgh, EH9 3JT, UK. smctagga@staffmail.ed.ac.uk.|Centre for Immunity, Infection and Evolution, School of Biological Sciences, Ashworth Laboratories University of Edinburgh, Edinburgh, EH9 3JT, UK. smctagga@staffmail.ed.ac.uk.
Seanna J
SJ
McTaggart
Centre for Environment, Fisheries and Aquaculture Science, The Nothe, Barrack Road, Weymouth, Dorset, DT4 8UB, UK. tidburyhannah@gmail.com.
Tidbury
T
Hannah
Edinburgh Genomics, Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories University of Edinburgh, Edinburgh, EH9 3JT, UK. Stephen.Bridgett@ed.ac.uk.
Stephen
S
Bridgett
Institute of Evolutionary Biology, School of Biological Sciences, Ashworth Laboratories University of Edinburgh, Edinburgh, EH9 3JT, UK. jennie.garbutt@gmail.com.
Jennie S
JS
Garbutt
The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada. gaganjot.kaur@sickkids.ca.
Gaganjot
G
Kaur
Daphne du Maurier Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Cornwall, TR10 9EZ, UK. M.Boots@exeter.ac.uk.
Mike
M
Boots
D000818:Animals; D016367:Baculoviridae / Q000502:physiology*; D016678:Genome; D054884:Host-Pathogen Interactions; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D009036:Moths / Q000235:genetics* / Q000378:metabolism / Q000821:virology*; D059467:Transcriptome
D019476:Insect Proteins; C047663:cuticle proteins, insects