Researches

The principal research activities of the Developmental Biology field are directed to the study of the molecular mechanisms of cell and tissue differentiation at molecular and cellular levels with muscle cells as a principal model system. The Cell Biology field investigates the roles of cell-cell and tissue interactions during the course of the development of multicellular organs. Studies on DNA structure and its functions enable us to understand the biological processes of organisms at the molecular level. The Molecular Biology field aims to clarify 1) the structures and functions of gene-transcription factors which regulate development, differentiation and carcinogenesis and 2) the mechanisms of cell growth and differentiation. One of the fundamental characteristics of a living organism is its ability to move. In the Physiology field, the proteins in the motile systems including myosin, connectin and other cytoskeletal or contractile proteins are studied by the methodologies of molecular biology, biophysics, and biochemistry. Ecology is a field of biology that studies the interrelationship between organisms and their environment. Current research topics of the Ecology field include community and population ecology of coastal ecosystems and ecophysiology in freshwater wetlands. Phylogenetics is a field of biology in which the history and mechanisms of evolution of organisms are studied. Research in the broader field of evolution in vascular plants is undertaken in the Phylogenetics field focusing on 1) speciation in ferns and Gymrosperms, 2) molecular systematics of land plants, and 3) analysis of Cretaceous fossil plants.

Molecular Biology

Life is conducted by genes/DNA. This means that studies on DNA structure and its function enable us to understand biological processes of the organisms at molecular level. Among cellular components, proteins play important roles in cells as structural components, enzymes, regulatory factors, etc. As the protein is encoded by DNA, we can study structure and functions of proteins from DNAs. At present time, it is possible to isolate/clone a desired DNA by recombinant DNA technology, then we can easily study complicated biological mechanisms by using cloned DNAs. For example, we determine DNA structure, produce proteins from cloned DNAs, obtain antibodies, and analyze gene function. In these days, we know many biological techniques concerning DNA are useful tools for our life. In our research division, by using molecular biological methods, we are studying structures and functions of transcription factors which regulate development, differentiation and carcinogenesis. Moreover, we study the mechanisms of cell growth and differentiation.

• Takeshi Endo (Professor, Ph. D.)
  Studies on the mechanisms of cell growth and differentiation
• Michio Ogasawara (Associate Professor, D. Sc.)
  Molecular and Developmental Evolution
• Kazuyoshi Takano (Assistant Professor, Ph. D)
  Studies on the mechanisms of cell growth and differentiation

Molecular Physiology

One of the fundamental characteristics of living organisms is their ablity to move. Many animals familiar to us use muscles to move. Actin and myosin, proteins responsible for muscle contraction, are also involved in a variety of motile activities in both animal and plant cells. Such activities include cell crawling, cytokinesis, vesicular transport and cytoplasmic streaming. We are studying these motile systems at molecular level. Many kinds of proteins involved in these motile systems have been purified in our laboratory. Those include myosin from invertebrate muscle, from microorganism, and even from plant, connectin, a gigantic elastic protein from vertebrate and invertebrate muscles, and several cytoskeletal or contractile proteins from vertebrate skeletal and smooth muscles. Molecular cloning of genes encoding some of these proteins had already been accomplished. Their characteristics, physiological functions, and locations in these motile systems are studied using biophysical, biochemical, immunochemical and molecular biological techniques.

• Kiyoe Ura (Professor, D. Sc.)
  chromatin metabolism and epigenetics
• Koji Ito (Professor, D. Sc.)
  Molecular Physiology of Plant. Regulation of cell-cell communication by Golgi kinases
• Asako Terasaki (Associate Professor, Ph. D)
  Contractile and Cytoskeletal Proteins in Smooth Muscle
• Akira Sassa (Assistant Professor, Ph.D.)
  chromatin metabolism and epigenetics

Cellular Biology

All organisms consist of "cells". If you try to examine a single cell very carefully, you will be able to reach understanding of a whole organism which is an assembly of cells. Conversely, no matter how profoundly you try to investigate a single cell, you will not be able to understand the characteristics of a multicellular organ in which each cell works in cooperation. Focusing on cell-cell and tissue interactions during the course of the development of multicellular organs, we are aiming at elucidating the identities of such interactions.

• Akira Matsuura (Professor, D. Sc.)
  Cell biology of yeast
• Hiroyuki Ishikawa (Associate Professor, Ph.D.)
  cytoskeleton
• Eisuke Itakura (Assistant Professor, Ph. D)
  Cell biology of yeast

Developmental Biology

Animal body consists of various cells such as skin cells, muscle cells, neurons and gut cells. According to species-specific developmental program these progenitor cells derived from a single cell, a fertilized egg, move to appropriate positions and differentiate there. The principal research activities of this group are directed to the study of the mechanisms of cell and tissue differentiation and morphogenesis at molecular and cellular levels. The following three research programs are under investigations.

1. Studies on the action of growth factors and extracellular matrices upon the branching morphogenesis of mouse salivary gland and lung.
2. Studies on the dynamics of a contractile system responsible for frog gastrulation.
3. Studies on cell-cell and cell-substrate interactions which are involved in the muscle morphogenesis and differentiation.

• Hiroshi Abe (Associate Professor, Ph.D.)
  Dynamics of Cytoskeleton during Development
• Naruki Sato (Associate Professor, Ph.D.)
  The roles of Cell-cell Interaction during Morphogenesis

Ecology

Ecology is a field biology that studies the organisms and their environment and the interrelationship between the two in outdoor. The ecological phenomena range in vast scales of space and time, and in levels of ecological organization from an individual (even a part of them such as leaf, stem, and root), population, community, to ecosystem. Thus the hierarchical approach is used to be taken to investigate the phenomena. Our research topics are geographical ecology of vegetation in mountains, forest dynamics, dynamics of grassland vegetation, population ecology of weeds, ecology of aquatic macrophytes, etc. In these days there is no intact nature in the world any more, thus it is essential to take into consideration of the human impacts on natural ecosystem. We are keen to study the gradational changes of ecosystem from urban, human centered, man-dominated system, through agricultural system, to natural system of the intact nature.

• Takayoshi Tsuchiya (Professor, D. Sc.)
  Ecology of Aquatic Macrophytes
• Masashi Murakami (Associate Professor, Ph.D.)
  community ecology
• Yuma Takahashi (Assistant Professor, Ph.D.)
  Evolutionary population biology

Phylogeny

There are so many organisms on the earth. They were originated probably from common ancestor, and evolved and diverged over more than 3,000 million years. Phylogenetics is a field of biology in which history and mechanisms of evolution of those organisms were studied. In our laboratory, researches of broader field of evolution in vascular plants are now progressed as follows. 1) Study of speciation in ferns and Lycoris using karyological and electrophoretic techniques. 2) Molecular systematics of Angiosperms using DNA sequence data. 3) Analysis of Cretaceous fossil plants, mainly Gymnosperms, with comparison of extant plants.

• Yasuyuki Watano (Professor)
  plant evolution and speciation, phylogeography, molecular ecology molecular phylogeny of plants, phylogeography
• Takashi Tsuchimatsu (Associate Professor)
  Plant Evolutionary Genomics
• Takeshi A. Ohsawa (Lecture)
  Paleobotany and molecular phylogeny of seed plant