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

1.1 .用简约法从COI、COII和16SrRNA基因的2120bps DNA序列中推断出鼻白蚁宿主白蚁的系统发育，共包括14属。对从鼻白蚁宿主中分离的假毛菌sp . sssurrna基因进行了测序，并对其系统发育进行了重建。除了来自同一寄主物种的克隆外，寄主和共生体的系统发育显示拓扑结构的一致性，表明曾经有过共种形成。此外，对寄主Reticulitermes spp.和共生体Teranynpha spp.也进行了类似的比较分析，除了来自两个寄主种群的克隆外，还推断了它们过去的共种关系。3 .原生生物群落进化和多样化过程的推断利用每个共生属的特征（有无）映射，在鼻白蚁的系统发育树上重建了过去的共生属多样化和寄主切换。寄主菌落大小对共生群落多样性的影响通过对白蚁实验菌落3个月的监测，研究寄主菌落大小对共生群落多样性的影响。群落大小的减小显著降低了群落的物种数量和Shannon指数。研究了日本及周边地区白蚁寄主Teranympha spp. SSUrRNA基因的遗传多样性。山口种群和爱知种群的序列多样性约为其他种群的10倍。这些种群的基因克隆可能受到了天燕孤雌生殖造成的谱系分选的影响。寄主白蚁的繁殖方式采用野外调查和DNA基因分型的方法，对甘肃白蚁和白蚁的繁殖方式进行了研究。建议近交和融合田间菌落。

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.