title: Amphibians have immunoglobulins similar to ancestral IgD and IgA from Amniotes.
abstract: We studied the immunoglobulin genes from either the genomes or RNAs of amphibians. In particular, we obtained data from one frog genome (Nanorana parkeri) and three transcriptomes of the Caudata order (Andrias davidianus, Notophthalmus viridescens and Cynops pyrrhogaster). Apart from the immunoglobulins IgM and IgY previously described, we identified several IgD related immunoglobulins. The species N. parkeri, N. viridescens and C. pyrrhogaster have two IgD genes, while Andrias davidianus has three such genes. The three Caudata species have long IgD immunoglobulins similar to IgD of reptiles, and could be an ancient relic from the common ancestor of IgD of all mammals and reptiles. We also found two IgA isotypes. The results suggest that one of the IgA may be the ancestor of IgA in crocodiles and birds, while the other could be the ancestor IgA found in mammals. These results provide information that could help understand the evolution of immunoglobulins in terrestrial vertebrates.
authors.affiliation: Area de Inmunología, Facultad de Biología, University of Vigo, 36310 Vigo, Spain. Electronic address: olivieri@ei.uvigo.es.
authors.forename: Olivia
authors.initials: O
authors.lastname: Estevez
authors.affiliation: Area de Inmunología, Facultad de Biología, University of Vigo, 36310 Vigo, Spain.
authors.forename: Elina
authors.initials: E
authors.lastname: Garet
authors.affiliation: School of Computer Science, University of Vigo, Ourense 32004, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Olivieri
authors.affiliation: Servicio Gallego de Salud (SERGAS), Unidad de Inmunología, Hospital do Meixoeiro, 36210 Vigo, Spain. Electronic address: fgambon@gmail.com.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gambón-Deza
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000235:genetics*; D000663:Amphibians / Q000235:genetics*; D000818:Animals; D005075:Biological Evolution; D005803:Genes, Immunoglobulin; D007070:Immunoglobulin A / Q000235:genetics*; D007072:Immunoglobulin D / Q000235:genetics*; D007132:Immunoglobulin Isotypes / Q000235:genetics; D008969:Molecular Sequence Data
chemical_list: D029845:Amphibian Proteins; D007070:Immunoglobulin A; D007072:Immunoglobulin D; D007132:Immunoglobulin Isotypes
keywords: Amphibian immunoglobulins; Evolution of immunoglobulins