Project/Area Number |
14540641
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
系統・分類
|
Research Institution | Nagoya University |
Principal Investigator |
KUMAZAWA Yoshinori Nagoya University, Graduate School of Science, Assistant Professor, 大学院・理学研究科, 講師 (60221941)
|
Co-Investigator(Kenkyū-buntansha) |
NISHIDA Mutsumi University of Tokyo, Ocean Research Institute, Professor, 海洋研究所, 教授 (90136896)
|
Project Period (FY) |
2002 – 2004
|
Project Status |
Completed (Fiscal Year 2004)
|
Budget Amount *help |
¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥2,000,000 (Direct Cost: ¥2,000,000)
|
Keywords | lizards / snakes / mitochondrial DNA / molecular phylogeny / divergence time / gene organization / vicariance / biogeography / 爬虫類 / PCR / 分子系統解析 / 高次系統分類 / 系統樹 |
Research Abstract |
During the granted period, we have sequenced mitochondrial DNAs of various reptiles. These data have been characterized in both the evolution of mitochondrial genome organization and the pattern and timing of phylogenetic divergences. We found that mtDNAs of some reptile groups (e.g., snakes, varanids, agamids, and cordylids) have distinct gene organizations from the typical organization found in most vertebrates. We then addressed when and how these gene rearrangements took place on ancestral lineages of each group by comparing sequences of the corresponding mtDNA region among relevant taxa. With respect to phylogenetic matters, the following implications were obtained. 1) Lacertilia can be divided into four groups mostly corresponding to infraorders suggested by morphological studies, 2) Amphisbaenia is nested within Lacertilia and is the most closely related to Lacertidae, 3) Among the four lizard infraorders, Gekkota rather than Iguania diverged first, 4) Snakes are not closely related to Varanoidea, and 5) Lizard families have deep divergences extending to Triassic and Jurassic.
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