| Co-Investigator(Kenkyū-buntansha) |
KATO Makoto KYOTO UNIVERSITY, Graduate School of Human and Environmental Studies, Assoc. Prof, 大学院・人間・環境学研究科, 助教授 (80204494)
KATAKURA Haruo Hokkaido Univ., Graduate School of Science, Prof., 大学院・理学研究科, 教授 (40113542)
SOTA Teiji KYOTO UNIVERSITY, Graduate School of Science, Assoc. Prof., 大学院・理学研究科, 助教授 (00192625)
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| Research Abstract |
In this research, we analyzed speciation pattern and factors promoting species diversity in several insect groups including both predators and herbivores using molecular phylogenetic approaches.
(1) Species assemblage and phylogeography of tiger beetles Cicindela in Japanese seashores.
We used mitochondrial markers to reveal the colonization pattern of different species with different mandible sizes that coexist in seashores. The speciation of these tiger beetles occurred in the east Asian continental region and the Southeast Asian region. Size assortment process could be the major process in assemblage formation.
(2) Phylogeny, life history evolution, and natural hydridization in carabid beetles (subfamily Carabinae, Coleoptera)
We clarified divergence pattern in each of three major wingless groups in different continents, Carabus (Holarctic), Ceroglossus (South America) and Pamborus (Australia) using nuclear and mitochondrial DNA makers. In the subgenus Ohomopterus (genus Carabus), we ma
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de a detailed analysis for nuclear gene genealogy and mitochondrial gene genealogy, to reveal the pattern of radiation and reticulation among morphologically differentiated entities through natural hybridization. This study revealed the unusual extent of introgressive hybridization in Ohomopterus that may be associated with extreme divergence in their genital morphology.
(3) Phylogeny and life history evolution of the world bumblebees (genus Bombus, Hymenoptera)
We analyzed phylogeny of 66 species belonging to 23 subgenera of genus Bombus using three nuclear genes each containing a variable intron region. We established a robust phylogenetic hypothesis for this group and elucidated patterns in adaptive radiation. This analysis confirmed single origins of parasitic bumblebees and pocket makers. Frequent intercontinental migration resulted in some widely distributed taxonomic groups.
(4) Evolution of host races in the ladybird beetles Epilachna
We analyzed host-mediated reproductive isolation between host races of Epilachna beetles and with field experiments and molecular markers of gene flow. It was found that the host races are complexly affected by plant conditions and unstable, subject to hybrid formation.
(5) Differentiation and coexistence of Chrysolina angusticollis spcies complex
We analyzed nuclear and mitochondrial DNA sequences of this species complex, and found they attained a differentiation leading to sympatry of different lineages without host changes, a contrasting case with Epilachna beetles. Less
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