title: Cytogenetic mapping of immunoglobulin heavy chain genes in Antarctic fish.
abstract: The chromosomal location of the IgH locus has been analyzed in several bony fish of the Antarctic perciform group Notothenioidei. Two IgH probes were prepared from the species Trematomus bernacchii (family Nototheniidae, tribe Trematominae) and mapped onto the chromosomes of ten species belonging to the same genus (Trematomus) and in two outgroups, through one-color and two-color FISH. A single location of the IgH locus was found in the majority of the species examined, including the outgroups, whereas in four of them the IgH genes splited to two chromosomal loci. RT-PCR experiments revealed the presence of three allelic sequences in T. newnesi, a species in which the IgH genes were organized in two chromosomal loci. Possible pathways leading to IgH genes duplication during the diversification of trematomine fishes were inferred from the analysis of the FISH patterns in a phylogenetic context. The present work provides the first comprehensive picture of IgH genes organization at chromosomal level in a bony fish group.
authors.affiliation: Department of Biology, University of Genova, Viale Benedetto XV 5, Genova, Italy. pisano@unige.it
authors.forename: Eva
authors.initials: E
authors.lastname: Pisano
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Coscia
authors.forename: Federico
authors.initials: F
authors.lastname: Mazzei
authors.forename: Laura
authors.initials: L
authors.lastname: Ghigliotti
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Coutanceau
authors.forename: Catherine
authors.initials: C
authors.lastname: Ozouf-Costaz
authors.forename: Umberto
authors.initials: U
authors.lastname: Oreste
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D002874:Chromosome Mapping; D018076:DNA, Complementary / Q000032:analysis; D050438:Genes, Immunoglobulin Heavy Chain; D017404:In Situ Hybridization, Fluorescence; D010473:Perciformes / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny
chemical_list: D018076:DNA, Complementary