Laboratories

Message

 

The field of life science aims to achieve an objective understanding of life. We attempt to record everything from the origin of primitive life to the development of human emotion and intellect using genes and their expression, a language shared by all living organisms. In the 21st century, the “search for self” that is life science is sure to create great waves. Our new century demands that we search for harmony between human life and the environment from a perspective that differs from anything that has come before. In order to consider the earth of tomorrow, and maintain humanity and all the organisms that live on this planet, it is important that we learn, understand, and utilize life science. Together, let’s create tomorrow’s world in the classrooms of life science. Below are some of the groups conducting research.

 

Research Groups and Research in the Field of Biology

 

Professor Ryutaro Murakami

 

The process in which the fates of cells are decided in animal embryos is known as cellular differentiation. We now know that this process is made up of multiple steps, and each step is controlled by specific genes. By artificially inhibiting or promoting gene activity, we can learn the functions of these genes. In Figure A, the intestine of a fruit fly is shown in blue. Activating a gene called byn at the front of the embryo causes another intestine to form where the esophagus should be (Figure B).

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Professor Isamu Miyagawa

 

Mitochondria are often called the powerhouse of the cell, generating most of the energy necessary for us to live. Mitochondria possess their own DNA distinct from nuclear DNA, and a portion of required protein is synthesized within the structure. This suggests that mitochondria are the remnant of bacteria that once lived independently long ago. Using yeast fungus as a research specimen, we research how cells regulate the shape and number of mitochondria to match energy demands and how mitochondria reproduce and pass on their DNA to descendants.

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Professor Masahiro Fujishima, Associate Professor Manabu Hori

 

Just as organelles such as mitochondria and chloroplasts evolved from symbiotic bacteria within cells, intracellular symbiosis provides the driving force for cellular evolution. It is a universal biological phenomenon that continues to be repeated today. How did organisms in intracellular symbiosis come to protect themselves from the defense systems of their host cells, and how did they evolve to complete functions that support the host? We are researching the interaction of paramecium and its intracellular symbiotic bacteria (holospora and chlorella) to reveal the phenomena that occur during the initial stages of cellular evolution.

 

Cilia are evolutionarily advanced organelles, and most organisms have either cilia or flagella. Recent studies have shown that cilia are not merely locomotive devices tasked with the transport of cells and materials, but that they also possess critical sensor capabilities for receiving and transmitting signals. Paramecium aurelia, a type of ciliate, has approximately 700 cilia along its surface, each composed of over 500 different types of protein. We are investigating the mechanisms of these cilia and how their movement (speed, direction, shape) is controlled.

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Professor Yasuhiro Iwao, Assistant Professor Shuichi Ueno

 

Fertilization is critical to the initiation of life. Mechanisms in fertilization, such as the cellular adhesion and fusion of the egg and sperm and the initiation of birth are extremely similar from lower animals to higher animals such as humans and have been well preserved through evolution. We are investigating the molecular mechanisms of fertilization using the African clawed toad and the newt, model animals for fertilization and birth in vertebrate animals. We are also conducting research to reveal the mechanisms of embryo cleavage (cell division) on the molecular level.

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Professor Shigehiko Yumura, Associate Professor Yoshiaki Iwadate

 

Our bodies are filled with cells that actively move and divide. When bacteria invade the body, white blood cells assemble to ingest it. Skin cells are also actively dividing to create new skin. When cells become cancerous, they divide more actively than normal cells, sometimes moving to other organs. These phenomena occur as result of cells moving and changing their shapes. We are learning that cell activity and division is related to a structure composed of protein called the cytoskeleton. We are investigating how the cytoskeleton relates to changes in cell movement and shape using model organisms called cellular slime molds. For example, we visualize how the motor proteins that move cells work within the cell, and we are developing technology to measure the minute pulling force that this generates. We expect that this research will one day contribute to medicine, including the treatment of cancer. (The photo shows the spatial distribution of the pulling force created by a cell in false color. The red portion is where a large pulling force is occurring.)

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Associate Professor Masao Watanabe

 

Insects boast the greatest variety of any animal on earth. They use chemical sense to distinguish edible plants and the pheromones given off by the opposite sex. We are investigating the mechanisms of the cabbage moth (noctuidae), which clearly modifies its sexual pheromone responsiveness during the day and night.

 

Noctuidae also includes species that damage ripe fruits in orchards. Our research was involved in the development of facilities that used ultrasonic waves, such as those generated by bats, to drive away these insects.

 

We use a method known as backfill to investigate nerve tracts. The photo shows dyed nerve tracts from peripheral nerves within the suboesophageal ganglion and thoracic ganglion of larva.

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Associate Professor Akira Yamanaka

 

We are performing research related to photoperiodic secretory regulation in the seasonal expression of butterflies. The majority of butterflies express their seasonal form as determined by day length and temperature during their larval period. In the cocoon, hormones secreted by the brain create the different colors and shape of the butterfly’s body (seasonal form). However, because insect cranial nerve hormones are species specific, it is difficult to use similarities between the effects and mechanisms in the hormones of other species to determine those mechanisms.

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Assistant Professor Yumiko Harada

 

Living organisms possess biological clocks that measure the time of approximately one day. Just like us people, the biological clock of the African clawed toad is located in its brain. The photos are enlargements of the heads of two tadpoles: a wild tadpole (right) and an albino tadpole (left). Their transparent bodies allow us to see nerves extending from the left and right eyes to the brain, where the biological clock is located. By investigating the biological clock, we found that although their colors are different, both wild and albino tadpoles share the same genes and proteins.

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Assistant Professor Yuki Hara

 

The shape and size of the cell are highly variable among cell types and species. Together with these visible changes in cell "form", the "inside" of the cell is also varied. Especially, the shape, size and function of the organelles, are the structures enclosing with membranes inside the cell, are also varied and regulated by sensing information of the cell form. Our lab has a keen interest in one of the organelles, the cell nucleus having genetic material DNA inside, and is investigating mechanisms for regulating shape and size of the cell nucleus.

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Nucleus reconstructed in the test tube in frogs Xenopus laevis. Magenta: DNA, Green: membranes (including nuclear membranes and endoplasmic reticulum).

 

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Professor Makoto Akashi (Full time instructor at the Research Institute for Time Studies)

 

Why do we go to sleep and wake up around the same time every day? And why do we become jet lagged when traveling abroad? It’s because we have an autonomous clock keeping time in 24-hour increments in our bodies. This clock is known as the biological clock (circadian clock). The biological clock regulates the rhythm of all biological activity, including sleep, internal secretions and metabolic activity, in 24-hour periods. This allows living organisms to live compatibly with our environment. However, our modern lifestyles threaten the proper function of our biological clocks, increasing our risks for many ailments. We are investigating the functions of genes that create the biological clock using mainly mice and cultivated cells to conduct research with an eye towards medical deployment. At the Research Institute for Time Studies, there is a great deal of research exchange fusing humanities and science (including sociology, history, psychology, philosophy and physics).

 

We observe the activity of biological clock genes with luminescence, using the genes of fireflies. The photo shows real time monitoring using luminescent imaging of the hypothalamus and supraoptic nucleus in the basal part of the diencephalon, the core of the biological clock. Each point of light is one of the nerve cells

that compose the supraoptic nucleus.

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