| Project/Area Number |
14596001
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物多様性・分類
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| Research Institution | Ibaraki University |
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Principal Investigator |
KITADE Osamu Ibaraki University, Faculty of Science, Associate Professor, 理学部, 助教授 (80302321)
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| Co-Investigator(Kenkyū-buntansha) |
KOJIMA Jun-ich Ibaraki University, Faculty of Science, Professor, 理学部, 教授 (00192576)
MIWA Isoji Ibaraki University, Faculty of Science, Professor, 理学部, 教授 (00007816)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | termites / symbiosis / protist / diversity / genetic variation / parthenogenesis / 共生微生物 / 群集 / 分子系統 |
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| Research Abstract |
1.Phylogeny reconstruction of Rhinotermitid host termites
Phylogeny of Rhinotermitid host termites, comprising of 14 genera, was inferred from DNA sequences (2120bps) of COI, COII and 16SrRNA genes using parsimony method.
2.Comparison of phylogenies between host termites and symbiotic protists
SSUrRNA gene of Pseudotrichonympha spp. isolated from the Rhinotermitid hosts was sequenced and their phylogeny was reconstructed. Except for clones from one host species, the phylogenies of the hosts and the symbionts indicated coincidence of the topology, suggesting past co-speciation. Similar comparative analysis was carried out for Reticulitermes spp. (hosts) and Teranynpha spp. (symbionts) and the past cospeciation was also inferred except for clones from two host populations.
3.Inference of evolution and diversification process of protist community
Using character (presence/absence) mapping of each symbiont genus, past diversification of symbiont genera and host switchings were reconstructed on the phylogenetic tree of the Rhinotermitidae.
4.Effect of host colony size on the diversity of symbiont community
Fron the 3 months' monitoring of experimental termite colonies, effects of host colony size on the diversity of symbiont community was investigated. The decrease of colony size significantly reduced the species numbers and Shannon index of the community.
5.Genetic diversity between symbiont individuals and population
Variation of SSUrRNA gene was investigated on Teranympha spp. from Reticulitermes hosts in and around Japan. In Yamaguchi population and Aichi population, sequence diversity were about 10 times higher than other populations. Gene clones from such populations were probably affected by lineage sorting caused by parthenogenesis of Teranympha.
6.Mode of reproduction of host termites
The mode of reproduction in Reticulitermes kanmonensis and R.speratus were investigated by field investigation and DNA genotyping. Inbreeding and fusion of field colonies were suggested.
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