title: The immunoglobulin δ gene in jawed vertebrates: a comparative overview.
abstract: Immunoglobulin D (IgD) was recently suggested to be an ancient Ig class, as old as IgM, arising approximately 500 million years ago. Its encoding gene has now been identified in nearly all classes of jawed vertebrates (except birds). Variance in the number of CH encoding exons and alternative RNA splicing confers this Ig class a marked structural plasticity, which differs substantially from IgM. Expression of the δ gene can be achieved through co-transcription with the μ gene or by class switching. Although a recent study has suggested that IgD functions as an immunomodulator in immunity and inflammation in humans, its functions are still far from clear. Further studies at the protein levels in additional species may help answer this question.
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Wei
authors.forename: Lennart
authors.initials: L
authors.lastname: Hammarstrom
authors.forename: Yaofeng
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D017398:Alternative Splicing / Q000276:immunology; D000818:Animals; D000916:Antibody Diversity; D019143:Evolution, Molecular; D006801:Humans; D056724:Immunity, Humoral / Q000235:genetics; D007072:Immunoglobulin D / Q000235:genetics; D007075:Immunoglobulin M / Q000235:genetics; D010802:Phylogeny; D010828:Physiology, Comparative; D011487:Protein Conformation; D014714:Vertebrates
chemical_list: D007072:Immunoglobulin D; D007075:Immunoglobulin M