The acute transcriptional response of the coral Acropora millepora to immune challenge: expression of GiMAP/IAN genes links the innate immune response of corals with those of mammals and plants

Acropora millepora transcriptome from the National Center for Biotechnology Information, BioProject PRJNA200542. Submitted by ARC Centre of Excellence for Coral Reef Studies, James Cook University.Experiment type: Expression profiling by high throughput sequencing.Summary: This studies investigates the acute response of the coral Acropora millepora to two immunogenes: MDP (bacterial mimic) and pIC (viral mimic). Three members of the GiMAP familly were found to respond strongly to MDP treatment, showing analalogy to the immune response in vertebrates and plants.Overall design: Differential gene expression following treatment with two immunogenes.Abstract [Related Publication]: Background: As a step towards understanding coral immunity we present the first whole transcriptome analysis of the acute responses of Acropora millepora to challenge with the bacterial cell wall derivative MDP and the viral mimic poly I:C, defined immunogens provoking distinct but well characterised responses in higher animals.Results: These experiments reveal similarities with the responses both of arthropods and mammals, as well as coral-specific effects. The most surprising finding was that MDP specifically induced three members of the GiMAP gene family, which has been implicated in immunity in mammals but is absent from Drosophila and Caenorhabditis. Like their mammalian homologs, GiMAP genes are arranged in a tandem cluster in the coral genome.Conclusions: A phylogenomic survey of this gene family implies ancient origins, multiple independent losses and lineage-specific expansions during animal evolution. Whilst functional convergence cannot be ruled out, GiMAP expression in corals may reflect an ancestral role in immunity, perhaps in phagolysosomal processing.The full methodology is available in the Open Access publication from the Related Publications link below.