Keio University

7 ARTICLES PUBLISHED IN JoVE

Medicine

Visualization and Analysis of Blood Flow and Oxygen Consumption in Hepatic Microcirculation: Application to an Acute Hepatitis Model

Kosuke Tsukada¹, Makoto Suematsu^2,3

¹Department of Applied Physics and Physico-Informatics, Keio University, ²Department of Biochemistry, School of Medicine, Keio University, ³Exploratory Research for Advanced Technology (ERATO), Suematsu Gas Biology Project, Japan Science and Technology Agency (JST)

An optical system was developed to visualize hepatic microcirculation with FITC-labeled erythrocytes and to measure the partial pressure of oxygen in the microvessels with laser-assisted phosphorimetry. This method can be used to investigate physiological and pathological mechanisms by analyzing microvascular structure, diameter, blood flow velocity, and oxygen tension.

Biology

The Green Monster Process for the Generation of Yeast Strains Carrying Multiple Gene Deletions

Yo Suzuki¹, Jason Stam¹, Mark Novotny², Nozomu Yachie³, Roger S. Lasken², Frederick P. Roth^3,4

¹Department of Synthetic Biology and Bioenergy, J. Craig Venter Institute, ²Department of Microbial and Environmental Genomics, J. Craig Venter Institute, ³Donnelly Centre & Department of Molecular Genetics, University of Toronto, ⁴Lunenfeld Research Institute, Mt Sinai Hospital

The Green Monster method enables the rapid assembly of multiple deletions marked with a reporter gene encoding green fluorescent protein. This method is based on driving yeast strains through repeated cycles of sexual assortment of deletions and fluorescence-based enrichment of cells carrying more deletions.

Engineering

Capillary-based Centrifugal Microfluidic Device for Size-controllable Formation of Monodisperse Microdroplets

Masamune Morita¹, Hitoyoshi Yamashita^1,2, Masayuki Hayakawa¹, Hiroaki Onoe³, Masahiro Takinoue^1,4

¹Department of Computational Intelligence and Systems Science, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, ²Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, ³Department of Mechanical Engineering, Keio University, ⁴PRESTO, Japan Science and Technology Agency

Here, we demonstrate a simple production method for size-controllable, monodisperse, water-in-oil (W/O) microdroplets using a capillary-based centrifugal microfluidic device. This method requires only a small sample volume and enables high-yield production. We expect this method will be useful for rapid biochemical and cellular analyses.

Cancer Research

Induction and Diagnosis of Tumors in Drosophila Imaginal Disc Epithelia

Kenta Morimoto^1,2, Yoichiro Tamori¹

¹Structural Biology Center, National Institute of Genetics and Department of Genetics, School of Life Science, SOKENDAI, ²Graduate School of Media and Governance, Keio University

Mosaic clone analysis in Drosophila imaginal disc epithelia is a powerful model system to study the genetic and cellular mechanisms of tumorigenesis. Here we describe a protocol to induce tumors in Drosophila wing imaginal discs using the GAL4-UAS system, and introduce a diagnosis method to classify the tumor phenotypes.

Behavior

A Method to Study Adaptation to Left-Right Reversed Audition

Atsushi Aoyama^1,2

¹Faculty of Environment and Information Studies, Shonan Fujisawa Campus (SFC), Keio University, ²School of Information Environment, Tokyo Denki University

The present study proposes a protocol to investigate the adaptation to left-right reversed audition achieved only by wearable devices, using neuroimaging, which can be an effective tool for uncovering the adaptability of humans to a novel environment in the auditory domain.

Genetics

Ultralow Input Genome Sequencing Library Preparation from a Single Tardigrade Specimen

Yuki Yoshida^1,2, Sayuri Konno^1,3, Ryousuke Nishino^1,3, Yumi Murai^1,3, Masaru Tomita^1,2,3, Kazuharu Arakawa^1,2,3

¹Institute for Advanced Biosciences, Keio University, ²Systems Biology Program, Graduate School of Media and Governance, Keio University, ³Faculty of Environment and Information Studies, Keio University

Contamination during the genomic sequencing of microscopic organisms remains a large problem. Here, we show a method to sequence the genome of a tardigrade from a single specimen with as little as 50 pg of genomic DNA without whole genome amplification to minimize the risk of contamination.

Genetics

Use of Freeze-thawed Embryos for High-efficiency Production of Genetically Modified Mice

Hirofumi Nishizono^*1,2,3, Mohamed Darwish^*4,5, Hideki Uosaki^6,7, Nanami Masuyama^8,9,10, Motoaki Seki^8,11, Hiroyuki Abe³, Nozomu Yachie^8,9,10,12,13, Ryohei Yasuda¹

¹Max Planck Florida Institute for Neuroscience, ²Life Science Research Center, University of Toyama, ³Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, ⁴Graduate School of Innovative Life Science, University of Toyama, ⁵Department of Biochemistry, Faculty of Pharmacy, Cairo University, ⁶Division of Regenerative Medicine, Center for Molecular Medicine, Jichi Medical University, ⁷Division of Stem Cell Research and Drug Development, Center for Development of Advanced Medical Technology, Jichi Medical University, ⁸Synthetic Biology Division, Research Center for Advanced Science and Technology, University of Tokyo, ⁹Institute for Advanced Biosciences, Keio University, ¹⁰Graduate School of Media and Governance, Keio University, ¹¹Department of Molecular Oncology, Graduate School of Medicine, Chiba University, ¹²Department of Biological Sciences, School of Science, University of Tokyo, ¹³College of Arts and Sciences, University of Tokyo

Here, we present a modified method for cryopreservation of one-cell embryos as well as a protocol that couples the use of freeze-thawed embryos and electroporation for the efficient generation of genetically modified mice.