title: Further characterization of T cell receptor chains of marsupials.
abstract: cDNA clones encoding T cell receptor alpha (TCRalpha) and beta (TCRbeta) from the South American opossum, Monodelphis domestica were isolated and characterized. A single clone isolated encoding a TCRalpha chain was full length, containing the complete V (variable), J (joining) and C (constant) regions. Three partial cDNA clones were isolated for TCRbeta which contained complete C sequences. Phylogenetic analysis of the TCR Valpha revealed that the M. domestica sequence and a sequence from the Australian brushtail possum, Trichosurus vulpecula, belong to separate Valpha families and intersperse with sequences from eutherian mammals. Similar to results described for marsupial and eutherian light chains, diversity at the V region of the TCR is ancient and maintained. In contrast phylogenetic analysis of the TCR Calpha and Cbeta sequences from M. domestica, T. vulpecula, and other vertebrates revealed that the marsupial TCR C grouped together forming a sister group to eutherian mammals.
authors.affiliation: Department of Biology, University of New Mexico, 87131, Albuquerque, NM, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Baker
authors.forename: G H
authors.initials: GH
authors.lastname: Rosenberg
authors.forename: P
authors.initials: P
authors.lastname: Zuccolotto
authors.forename: G A
authors.initials: GA
authors.lastname: Harrison
authors.forename: E M
authors.initials: EM
authors.lastname: Deane
authors.forename: R D
authors.initials: RD
authors.lastname: Miller
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D006801:Humans; D008969:Molecular Sequence Data; D009893:Opossums / Q000235:genetics* / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000145:classification / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D016693:Receptors, Antigen, T-Cell, alpha-beta