title: Identification of two distinct types of beta-2 microglobulin in marine fish, Pagrus major and Seriola quinqueradiata.
abstract: Two types of beta-2 microglobulin (beta2m) were identified in red seabream and yellowtail from expressed sequence tag (EST) analyses of kidney and spleen cells. A cluster of 21 ESTs from red seabream showed high homology to beta2m from other teleosts, while another cluster containing 7 ESTs was also homologous to beta2m. Similarly, two clusters containing 21 and 2 ESTs were identified to be homologous to beta2m in yellowtail. The genes in the large and small clusters of each fish were designated beta2m-1 and beta2m-2, respectively. Although the amino acid sequences of beta2m-1s were highly homologous to those identified in the other teleosts, those of beta2m-2s were less homologous to fish beta2m. beta2m-1 of red seabream lacks the first intron of two introns observed in vertebrates, and beta2m-2 lacks both introns. Phylogenetic analysis of vertebrate beta2m proteins suggested that the beta2m-2 in marine fish are distinct from beta2ms in the other teleosts.
authors.affiliation: Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan. h-kondo@kaiyodai.ac.jp
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Kondo
authors.forename: Damri
authors.initials: D
authors.lastname: Darawiroj
authors.forename: Yeu-Tzeh-Andrew
authors.initials: YT
authors.lastname: Gung
authors.forename: Motoshige
authors.initials: M
authors.lastname: Yasuike
authors.forename: Ikuo
authors.initials: I
authors.lastname: Hirono
authors.forename: Takashi
authors.initials: T
authors.lastname: Aoki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D020224:Expressed Sequence Tags; D007438:Introns; D008285:Major Histocompatibility Complex; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny; D021541:Sea Bream / Q000235:genetics* / Q000276:immunology; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D001613:beta 2-Microglobulin / Q000145:classification / Q000235:genetics* / Q000276:immunology
chemical_list: D001613:beta 2-Microglobulin; D004247:DNA