title: Evolutionary stability of the immunoglobulin heavy chain variable region gene families in teleost.
abstract: A comparison between related species would allow us to study the evolutionary changes in complex gene families. To investigate the evolution of immunoglobulin VH gene families in lower vertebrates, we compared cDNA VH clones from two related teleost fish species, Arctic charr (Salvelinus alpinus) and rainbow trout (Oncorhynchus mykiss), which are separated from their common ancestor by 12-20 million years (MY). The results showed that randomly isolated charr VH genes could be closely grouped to known VH genes of rainbow trout, suggesting that the VH family structure is stable during 12-20 MY and that the total number of VH families changes only gradually over a longer period. This finding also led us to define eight VH gene families of Arctic charr, designated Salalp VH I, VH II, and so on. The presence of species-specific amino acids suggests that non-reciprocal genetic exchanges (e.g., gene duplication) play an important role in shaping the evolution of the V gene family.
authors.affiliation: Department of Immunology, University of Umea, S-901 85 Umea, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Andersson
authors.forename: T
authors.initials: T
authors.lastname: Matsunaga
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics* / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007133:Immunoglobulin Joining Region / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D007143:Immunoglobulin Heavy Chains; D007133:Immunoglobulin Joining Region; D007135:Immunoglobulin Variable Region