15 research outputs found
[4+2] Cycloaddition of 9-Anthryldiphosphene with Electron-Deficient Olefins: Transformation of a Diaryldiphosphene to Alkylaryldiphosphenes
A Ferrocenyldiphosphene−Platinum Complex: Structural Features and Theoretical Calculations
Synthesis and Properties of a Rhodium Complex Having a Novel b-Ketophosphenato Ligand, a Heavier Congener of a b-Ketoiminato Ligand
Synthesis, Structures, and Reactivity of Kinetically Stabilized Anthryldiphosphene Derivatives
Hybrid identification of “Sakemasu” collected in the Nemuro Strait, eastern Hokkaido, using DNA analysis
Synthesis of a Rhodium Carbonyl Phosphaalkenyl–Phosphido Complex: A Phosphorus Congener of Schiff Base Type N,N′-Chelating Monoanionic Ligands
Evolution and divergence of sodium channel genes in vertebrates
Invertebrate species possess one or two Na(+) channel genes, yet there are 10 in mammals. When did this explosive growth come about during vertebrate evolution? All mammalian Na(+) channel genes reside on four chromosomes. It has been suggested that this came about by multiple duplications of an ancestral chromosome with a single Na(+) channel gene followed by tandem duplications of Na(+) channel genes on some of these chromosomes. Because a large-scale expansion of the vertebrate genome likely occurred before the divergence of teleosts and tetrapods, we tested this hypothesis by cloning Na(+) channel genes in a teleost fish. Using an approach designed to clone all of the Na(+) channel genes in a genome, we found six Na(+) channel genes. Phylogenetic comparisons show that each teleost gene is orthologous to a Na(+) channel gene or gene cluster on a different mammalian chromosome, supporting the hypothesis that four Na(+) channel genes were present in the ancestors of teleosts and tetrapods. Further duplications occurred independently in the teleost and tetrapod lineages, with a greater number of duplications in tetrapods. This pattern has implications for the evolution of function and specialization of Na(+) channel genes in vertebrates. Sodium channel genes also are linked to homeobox (Hox) gene clusters in mammals. Using our phylogeny of Na(+) channel genes to independently test between two models of Hox gene evolution, we support the hypothesis that Hox gene clusters evolved as (AB) (CD) rather than {D[A(BC)]}