Laboratory for Chromosome Segregation
- Location：Kobe / Developmental Biology Buildings
- E-mail：tomoya.kitajima[at]riken.jpPlease replace [at] with @.
- Lab Website
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.。
Chromosome segregation error
Plk1 localization at kinetochores and MTOCs
- 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