Laboratory for Chromosome Segregation | RIKEN BDR

Laboratory for Chromosome Segregation

Team Leader

Tomoya KitajimaPh.D.

  • Location:Kobe / Developmental Biology Buildings
  • E-mail:tomoya.kitajima[at]riken.jpPlease replace [at] with @.
  • Lab Website

Research Summary

The oocyte becomes an egg through meiosis. The egg fertilizes with a sperm and undergoes repeated cell divisions to give rise to an entire body. We study chromosome segregation during meiosis in oocytes and during mitosis in fertilized eggs, taking advantage of techniques for high-throughput and high-resolution live imaging of mouse oocytes combined with micromanipulation and genetic engineering methods. The first cell division that oocytes undergo is meiosis I. Chromosome segregation in this division is error-prone and the rate of errors increases with maternal age. Subsequently, chromosomes are segregated in meiosis II upon fertilization, and then segregated again in mitosis after DNA replication. We will reveal distinct mechanisms for chromosome segregation during these subsequent but fundamentally different cell divisions. By uncovering the mechanism of chromosome segregation during meiosis I in oocytes, we understand why oocyte meiosis I is error-prone and related to age. Comparing the mechanisms in meiosis I with those found in meiosis II and mitosis may provide insights into the capacity of cells to flexibly use different strategies for chromosome segregation. The findings will be exploited to collaborative studies with reproductive medicine.。

Kinetochore-microtubule attachments

Chromosome segregation error

Plk1 localization at kinetochores and MTOCs

Research Theme

  • Analysis of the mechanisms underlying meiotic chromosome segregation in mammalian oocytes
  • Study of the mechanisms underlying chromosome segregation during mitosis in fertilized eggs
  • Age-related errors in oocytes and fertilized eggs

Main Publications List

  • Ding Y, Kaido M, Llano E, et al.
    The post-anaphase SUMO pathway ensures the maintenance of centromeric cohesion through meiosis I-II transition in mammalian oocytes
    Current Biology 2018. doi: 10.1016/j.cub.2018.04.019
  • Kyogoku H and Kitajima TS.
    Large cytoplasm is linked to the error-prone nature of oocytes.
    Developmental Cell 41(3). 287–298 (2017) doi :10.1016/j.devcel.2017.04.009
  • Sakakibara Y, Hashimoto S, Nakaoka Y, et al.
    Bivalent separation into univalents precedes age-related meiosis I errors in oocytes.
    Nature Communications 6. 7550 (2015) doi:10.1038/ncomms8550
  • Yoshida S, Kaido M, and Kitajima TS.
    Inherent instability of correct kinetochore-microtubule attachments during meiosis I in oocytes.
    Developmental Cell 33(5). 589–602 (2015) doi:10.1016/j.devcel.2015.04.020
  • Kim J, Ishiguro K, Nambu A, et al.
    Meikin is a conserved regulator of meiosis-I-specific kinetochore function.
    Nature 517(7535). 466–471 (2015) doi:10.1038/nature14097
  • Solc P, Kitajima TS, Yoshida S, et al.
    Multiple requirements of PLK1 during mouse oocyte maturation.
    PLOS ONE 10(2). e0116783 (2015) doi:10.1371/journal.pone.0116783
  • Kitajima TS, Ohsugi M, and Ellenberg J.
    Complete kinetochore tracking reveals error-prone homologous chromosome biorientation in mammalian oocytes.
    Cell 146. 568–581 (2011) doi:10.1016/j.cell.2011.07.031

All Publications