title: Tandem duplications in the C-terminal domain of the mesotocin receptor exclusively identified among East Eurasian thrushes.
abstract: Mesotocin is a neurohypophyseal hormone found in some non-mammalian vertebrates, including birds, reptiles, and amphibians. In this study, we identified and characterized 18-amino acid duplications in the C-terminal domain of the mesotocin receptor (MTR), specifically found in Turdus thrushes (Aves: Passeriforms: Turdidae). These duplicated elements are located in the distal part of the C-terminal tails of MTR and consist of amino acids that are highly conserved among major vertebrates. Intraspecific polymorphisms in a variable number of tandem duplications are commonly found in East Eurasian Turdus, but not in any other genus of Turdidae. Moreover, the genus Turdus can be further classified into 2 groups according to the presence or absence of a 3-amino acid deletion just adjacent to the putative palmitoylation site in the cytoplasmic C-terminal tail. The phylogeny presented here strongly supports the conspecific group of 4 East Eurasian thrushes (Turdus pallidus, T. chrysolaus, T. obscurus, and T. celaenops). Our findings, therefore, provide a new synapomorphy that can be used for phylogenetic assumptions and shed a light on the history of diversification within Eurasian Turdus clades.
authors.affiliation: Wildlife Research Center, Kyoto University, 2-24 Tanaka-Sekiden-cho, Sakyo-ku, Kyoto, 606-8203, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Abe
authors.forename: Isao
authors.initials: I
authors.lastname: Nishiumi
authors.forename: Miho
authors.initials: M
authors.lastname: Inoue-Murayama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D005838:Genotype; D008969:Molecular Sequence Data; D046109:Passeriformes / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D011979:Receptors, Pituitary Hormone / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012732:Sex Determination Analysis; D013045:Species Specificity; D020080:Tandem Repeat Sequences / Q000235:genetics*
chemical_list: D017931:DNA Primers; D011979:Receptors, Pituitary Hormone; C116046:mesotocin receptor