title: Immune-related functions of the Hivep gene family in East African cichlid fishes.
abstract: Immune-related genes are often characterized by adaptive protein evolution. Selection on immune genes can be particularly strong when hosts encounter novel parasites, for instance, after the colonization of a new habitat or upon the exploitation of vacant ecological niches in an adaptive radiation. We examined a set of new candidate immune genes in East African cichlid fishes. More specifically, we studied the signatures of selection in five paralogs of the human immunodeficiency virus type I enhancer-binding protein (Hivep) gene family, tested their involvement in the immune defense, and related our results to explosive speciation and adaptive radiation events in cichlids. We found signatures of long-term positive selection in four Hivep paralogs and lineage-specific positive selection in Hivep3b in two radiating cichlid lineages. Exposure of the cichlid Astatotilapia burtoni to a vaccination with Vibrio anguillarum bacteria resulted in a positive correlation between immune response parameters and expression levels of three Hivep loci. This work provides the first evidence for a role of Hivep paralogs in teleost immune defense and links the signatures of positive selection to host-pathogen interactions within an adaptive radiation.
authors.affiliation: Zoological Institute, University of Basel, 4051 Basel, Switzerland.
authors.forename: Eveline T
authors.initials: ET
authors.lastname: Diepeveen
authors.forename: Olivia
authors.initials: O
authors.lastname: Roth
authors.forename: Walter
authors.initials: W
authors.lastname: Salzburger
mesh_terms: D000351:Africa, Eastern; D019943:Amino Acid Substitution; D000818:Animals; D023681:Cichlids / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000235:genetics* / Q000276:immunology; D005786:Gene Expression Regulation; D005796:Genes / Q000276:immunology; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D012045:Regulatory Sequences, Nucleic Acid; D012641:Selection, Genetic; D014611:Vaccination; D014733:Vibrio / Q000472:pathogenicity
chemical_list: D029941:Fish Proteins
keywords: adaptive radiation; immune response; molecular evolution; positive selection