Ikawa Lab/Genome Information Research Center  Department of Experimental Genome Research

In the past, animals harboring natural mutations have been used to elucidate the mechanisms underlying various diseases.
In the “post-genome project era,” genetically modified animals play a key role in basic molecular biological investigations and act as models of human disease. Our laboratory studies the mechanisms underlying mammalian reproductive systems through genetic manipulation of animal models.

Analysis of molecular mechanisms involved in mammalian gametogenesis, fertilization, and implantation

We were the first laboratory in the world to produce genetically modified mice that express green fluorescent protein (GFP) throughout the body (Fig. 1). These green fluorescent mice are useful for many types of research projects. Indeed, we used these animals to label sperm with fluorescent protein and visualize the fertilization process (Exp Anim. 2010; JCS. 2010, 2012; PNAS. 2012, 2013) (Fig. 2).
Recently, we found that calcineurin (PPP3CC/PPP3R2) is essential for sperm motility and male fertility (Science. 2015). Inhibiting sperm calcineurin may lead to the development of a reversible male contraceptive.

Development of new technologies for producing genetically modified animals

Another tool improved by work in our laboratory is lentiviral (LV) vector-mediated genetic manipulation in vivo. We developed the technique of placenta-specific gene manipulation by transducing blastocyst stage embryos with LV vectors (Nat Biotechnol. 2007; PNAS. 2011). Using this technique, we are trying to elucidate the mechanism underlying implantation and placentation.
We also established rat embryonic stem (ES) cells and generated mouse-rat chimeric animals. We would like to use this animal model to study body/organ size control in vivo; indeed, this method may enable derivation of various organs from ES or iPS cells (Genes Cell. 2011; Sci Rep. 2016).

Our recent interest is using the CRISPR/Cas9 system to generate genetically modified animals to study fertilization, implantation, and placentation. We have had success in mice and rats using sgRNA/Cas9-expressing plasmids (Sci Rep. 2013,2016; DGD. 2014; PNAS.2016; Nat. Commun. 2016).
Our laboratory and the Animal Resource Center for Infectious Diseases (http://www.arcid.biken.osaka-u.ac.jp/) offer support services such as generation of genetically modified animals, in vitro fertilization, and cryopreservation of mouse strains. For more information, please visit our homepage (http://www.egr.biken.osaka-u.ac.jp/index.php).

 

  • Fig. 1. GFP-expressing mice are useful for many types of research project. Genetically modified animals play a key role in basic molecular biology-based investigations and are good models for studying human disease.

  • Fig. 2. Mouse eggs (left) and sperm (right) labeled with fluorescent proteins. These gametes are used to visualize the fertilization process. (Figs from Exp. Anim. 59(1), 105-7, 2010)

Staff

  • Prof.: Masahito Ikawa(concur.)
  • Assoc. Prof.: Haruhiko Miyata
  • Assoc. Prof.: Norikazu Yabuta(concur.)
  • Asst. Prof.: Taichi Noda
  • Asst. Prof.: Keisuke Shimada
  • Asst. Prof.: Daiji Kiyozumi
  • SA Asst. Prof.: Tsutomu Endo (concur.)
  • SA Asst. Prof.: Julio Castaneda
  • SA Asst. Prof.: Lu Yonggang
  • JSPS Research Fellow: Nobuyuki Sakurai
  • JSPS Research Fellow: Yamauchi (Ishikawa) Yu
  • Guest Professor: Martin M. Matzuk
  • Guest Associate Professor: Yoshitaka Fujihara
  • Guest Researcher: Masaru Okabe

Website

Publications

  • (1) New Insights into the Molecular Events of Mammalian Fertilization. Satouh Y., e al., (2018) Trends Biochem Sci. 43(10):818-828
    (2) Sperm-borne phospholipase Czeta-1 ensures monospermic fertilization in mice. Nozawa K., et. al., (2018) Sci Rep. 8(1):1315.
    (3) TCTE1 is a conserved component of the dynein regulatory complex and is required for motility and metabolism in mouse spermatozoa. Castaneda J.M., et al., PNAS (2018) 114 (27):E5370-E5378
    (4) Structural and functional insights into IZUMO1 recognition by JUNO in mammalian fertilization. Kato K., et al., Nat Commun. (2016) 7:12198.
    (5) Genome engineering uncovers 54 evolutionarily conserved and testis-enriched genes that are not required for male fertility in mice. Miyata H., et al., Proc Natl Acad Sci USA. (2016) 113(28):7704-10.
    (6) Sperm calcineurin inhibition prevents mouse fertility with implications for male contraceptive. Miyata H., et al., Science. (2015) 350(6259):442-5.