T. Nishiyama Research Information

Evolution of Complex Adaptive Traits

With the rapid development of next generation sequencers, it is now possible to tackle the genomes of non-model organisms and elucidate how complex adaptive traits evolved. We are developing efficient methods for deciphering non-model organism genomes by fully utilizing the next-generation sequencers and computers.

Land Plant Evolution

Comparative genomics approach

Plants landed 400-500 million years ago. The success of land plants were accompanied with the innovation of multicellular diploid body, vascular systems and many other developmental features. To understand the evolution of land plants, it is essential to comare the genomes of plants that diverged eary during the land plant evolution and the charophycean green algae, which diverged prior to the establishment of the land plants.

We are studing the genomes of the moss, Physcomitrella patens, and the clubmoss Selaginella moellendorffii with many researchers over the world.

Transcriptome analysis of Charophycean green algae, Closterium peracerosum-strigosum-littorale complex, and Chara braunii are ongoing in collaboration with H. Sekimoto at Japan Women's University and H. Sakayama at kobe university.

Links

Physcomitrella patens genome information

Selaginella moellendorffii genome information

Land Plant Gene tree database at NIBB

Phylogeny of land plants

The phylogenetic relationships serves basic information for interpretation of gene trees and genome evolution. For the earliest branches of the extant land plants, the relationship is vague even with the all protein coding genes in chloroplast genomes. Although a broader taxonomic sampling data has strong bootstrap value that liverworts are basal, the strong gc content bias is evident and the bootstrap value cannot be taken as a good measure of the strength of the hypothesis. Thus, we are collecting sequences of many genes for broader taxa.