The mechanism to maintain ploidy during mammalian fertilization

• Project/Area Number: 17H05005
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Developmental biology
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Mori Masashi 国立研究開発法人理化学研究所, 生命機能科学研究センター, 研究員 (00747941)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥27,300,000 (Direct Cost: ¥21,000,000、Indirect Cost: ¥6,300,000); Fiscal Year 2019: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2017: ¥22,360,000 (Direct Cost: ¥17,200,000、Indirect Cost: ¥5,160,000)
• Keywords: 受精 / 卵子 / 精子 / 染色体 / アクチン / 異数体 / 卵母細胞 / 生殖

Outline of Final Research Achievements

This study investigated how chromosomes are localized during fertilization process. First, we established high resolution live imaging set up. These live imaging showed that sperm fuse far from maternal chromosomes. To control where sperm fuse, maternal chromosomes regulate the localization of membrane proteins on egg surface. After egg-sperm fusion, both maternal and paternal chromosomes move randomly, however they are not localized within 30-40 um.
The results of this study is useful to rise the success rate of infertility treatment like intra-cytoplasmic sperm injection.

Academic Significance and Societal Importance of the Research Achievements

近年不妊治療の技術が発達・普及し、顕微授精で生まれる子供も多くなっている。一方で、不妊治療後も原因不明のまま妊娠できないケースも多い。本研究の成果から精子染色体は卵子染色体の近傍に局在してはならないことが明らかになった。これは顕微授精を行う際に卵子染色体の局在を考慮することで、その成功率が上昇することを意味している。卵子染色体の観察については、すでに偏光顕微鏡等の非侵襲的な技術が確立されている。今後は不妊治療クリニックにおいて、卵子染色体の局在を観察したうえでの顕微授精が望まれる。

Research Products

• [Journal Article] Genetic mutation of <i>Frem3</i> does not causeFraser syndrome in mice (2020)
  • Author(s): Kiyozumi Daiji、Mori Masashi、Kodani Mayo、Ikawa Masahito
  • Journal Title: Experimental Animals Volume: 69 Issue: 1 Pages: 104-109
  • DOI: 10.1538/expanim.19-0088
  • NAID: 130007791541
  • ISSN: 0007-5124, 1341-1357, 1881-7122
  • Peer Reviewed / Open Access
• [Journal Article] F-Actin nucleated on chromosomes coordinates their capture by microtubules in oocyte meiosis (2018)
  • Author(s): Burdyniuk Mariia、Callegari Andrea、Mori Masashi、Nedelec Francois 、Lenart Peter
  • Journal Title: The Journal of Cell Biology Volume: 217 Issue: 8 Pages: 2661-2674
  • DOI: 10.1083/jcb.201802080
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A cdk1 gradient guides surface contraction waves in oocytes (2017)
  • Author(s): Bischof Johanna、Brand Christoph A.、Somogyi K?lm?n、M?jer Imre、Thome Sarah、Mori Masashi、Schwarz Ulrich S.、L?n?rt P?ter
  • Journal Title: Nature Communications Volume: 8 Issue: 1 Pages: 1-10
  • DOI: 10.1038/s41467-017-00979-6
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Embryo keeps paternal chromosomes away from maternal spindle not to discard them into polar body (2017)
  • Author(s): 森 雅志
  • Organizer: The 50th Annual Meeting of Japanese Society of Developmental Biologists
• [Presentation] マウス受精過程における精子染色体の極体放出防止機構 (2017)
  • Author(s): 森 雅志
  • Organizer: 2017年度生命科学系学会合同年次大会