Studies on the evolution of characters in the cephalochordates, based on molecular trees of many living species over the world
Project/Area Number |
13440253
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
系統・分類
|
Research Institution | Nagoya University |
Principal Investigator |
NISHIKAWA Teruaki Nagoya University, The Nagoya University Museum, Professor, 博物館, 教授 (50126885)
|
Co-Investigator(Kenkyū-buntansha) |
NISHIDA Mutsumi University of Tokyo, Ocean Research Institute, Professor, 海洋研究所, 教授 (90136896)
|
Project Period (FY) |
2001 – 2003
|
Project Status |
Completed (Fiscal Year 2003)
|
Budget Amount *help |
¥14,900,000 (Direct Cost: ¥14,900,000)
Fiscal Year 2003: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2002: ¥4,900,000 (Direct Cost: ¥4,900,000)
Fiscal Year 2001: ¥7,200,000 (Direct Cost: ¥7,200,000)
|
Keywords | Cephalochordata / Branchiostoma / Epigonichthys / mitochondrial DNA / cryptic species / phylogeny / evolution / characters / 形質進化 / 単系統群 / 分子進化 / 遺伝的距離 / 遺伝子配置変動 / コドン使用の変則 |
Research Abstract |
We have analyzed the whole mitochondrial genomes of far more than the half of the samples gained during the present project (24 populations of 15 species over the world) and got many important results as follows : (1) The uniqueness of Epigonichthys lucayanus has been revealed. (2) Paraphyly of the genus Epigonichthys has been proved, with the deepest branching between E.lucayanus (and its cryptic species, see below) and the remaining (consisting of its congeners and the species of the other recognized genus Branchiostoma) ; thus the Cephalochordata has proved to be divided into the three (instead of the two in the present system) genera. (3) E.lucayanus has been found to contain two species, which are indistinguishable morphologically from each other. (4) Molecular data of the European lancelet, Branchiostoma lanceolatum registered in the data bank of molecular information has been revealed quite different from our analyses of the same species from Helgoland and Napoli, instead similar to that of B.floridae from Florida ; this discrepancy is attributable to mis-identification of the data in the bank.
|
Report
(4 results)
Research Products
(3 results)