title: Isolation and comparison of the IgM heavy chain constant regions from Australian (Trichosurus vulpecula) and American (Monodelphis domestica) marsupials.
abstract: cDNAs encoding IgM heavy chain constant region (Cmu) were isolated from two metatherians (marsupials)--the Australian common brushtail possum (Trichosurus vulpecula) and the South American grey short-tailed opossum (Monodelphis domestica). Analysis of the sequences suggested that they correspond to the secreted form of Cmu in both species. The domain size and structure of the marsupial Cmu sequences were compared with other Cmu sequences and a high degree of conservation throughout vertebrate evolution was observed. Amino acid sequence comparisons revealed a marked level of sequence similarity between the two marsupial sequences (79%), relatively high similarity between the marsupials and eutherians (63%), and lower similarities between marsupials and birds (45%), marsupials and amphibians (47%), marsupials and reptiles (45%) and marsupials and fish (37%). These data allow the incorporation of metatherians into the study of mammalian IgM evolution.
authors.affiliation: Department of Biological Sciences, Macquarie University, NSW, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Belov
authors.forename: G A
authors.initials: GA
authors.lastname: Harrison
authors.forename: G H
authors.initials: GH
authors.lastname: Rosenberg
authors.forename: R D
authors.initials: RD
authors.lastname: Miller
authors.forename: D W
authors.initials: DW
authors.lastname: Cooper
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001315:Australia; D001483:Base Sequence; D018076:DNA, Complementary; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D007075:Immunoglobulin M / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D007148:Immunoglobulin mu-Chains / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009893:Opossums / Q000235:genetics / Q000276:immunology*; D013020:South America
chemical_list: D018076:DNA, Complementary; D007127:Immunoglobulin Constant Regions; D007075:Immunoglobulin M; D007148:Immunoglobulin mu-Chains