Studies on diversity and diversification process of instestinal flagellate communities of temites.

1.鼻白蚁寄主白蚁的系统发育利用简约法从白蚁COI、COII和16SrRNA基因的DNA序列(2120bps)推断了14个属的寄主白蚁的系统发育。2.寄主白蚁与共生原生生物系统发育的比较对其进行了序列测定，重建了它们的系统发育关系。除了来自一个寄主物种的克隆外，寄主和共生体的系统发育表明拓扑结构一致，表明过去存在共同物种形成。类似的比较分析也适用于网虫属种。(Hosts)和Teranynpha spp.利用每个共生体属的特征(有无)图，重建了共生体属的过去多样性和共生体的系统发育树。4.宿主群体大小对共生体群落多样性的影响通过3个月的白蚁实验群体监测，研究了宿主群体大小对共生体群落多样性的影响。种群规模的减小显著降低了群落的物种数和Shannon指数。5.共生体个体与种群间的遗传多样性研究了白蜡虫SSUrRNA基因的变异。来自日本及周边地区的寄主。山口种群和爱知种群的序列多样性约为其他种群的10倍。6.寄主白蚁的繁殖方式通过野外调查和DNA基因分型的方法，研究了甘蒙散白蚁和尖吻散白蚁的繁殖方式。提出了近亲交配和野外群体融合的建议。

1.Phylogeny reconstruction of Rhinotermitid host termitesPhylogeny 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 protistsSSUrRNA 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 communityUsing 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 communityFron 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 populationVariation 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 termitesThe 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.