Team Leader
Tomoya Kitajima
Ph.D.
Laboratory for Chromosome Segregation
Location Kobe / Developmental Biology Buildings
E-mail tomoya.kitajima[at]riken.jp
Please replace [at] with @.
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.
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
Selected Publications
Ogonuki N, Kyogoku H, Hino T, et al.
Birth of mice from meiotically arrested spermatocytes following biparental meiosis in halved oocytes.
EMBO Reports
23(7), e54992 (2022)
doi: 10.15252/embr.202254992
Mori M, Yao T, Mishina T, et al.
RanGTP and the actin cytoskeleton keep paternal and maternal chromosomes apart during fertilization.
The Journal of Cell Biology
220(10), e202012001 (2021)
doi: 10.1083/jcb.202012001
Mishina T, Tabata N, Hayashi T, et al.
Single-oocyte transcriptome analysis reveals aging-associated effects influenced by life stage and calorie restriction.
Aging Cell
20(8), e13428 (2021)
doi: 10.1111/acel.13428
Hamazaki N, Kyogoku H, Araki H, et al.
Reconstitution of the oocyte transcriptional network with transcription factors.
Nature
589, 264-269 (2021)
doi: 10.1038/s41586-020-3027-9
Courtois A, Yoshida S, Takenouchi O, et al.
Stable kinetochore-microtubule attachments restrict MTOC position and spindle elongation in oocytes.
EMBO Reports
22(4), e51400 (2021)
doi: 10.15252/embr.202051400
Yoshida S, Nishiyama S, Lister L, et al.
Prc1-rich kinetochores are required for error-free acentrosomal spindle bipolarization during meiosis I in mouse oocytes.
Nature Communications
11, 2652 (2020)
doi: 10.1038/s41467-020-16488-y
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
28(10), 1661-1669 (2018)
doi: 10.1016/j.cub.2018.04.019
Kyogoku H, 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
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
Yoshida S, Kaito M, 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
Kitajima TS, Ohsugi M, Ellenberg J.
Complete kinetochore tracking reveals error-prone homologous chromosome biorientation in mammalian oocytes.
Cell
146(4), 568-581 (2011)
doi: 10.1016/j.cell.2011.07.031
Members
Tomoya Kitajima
Team Leader
Shuhei Yoshida
Senior Scientist
Eishi Aizawa
Research Scientist
Osamu Takenouchi
Special Postdoctoral Researcher
Tappei Mishina
Special Postdoctoral Researcher
Hinako Takase
Visiting Researcher
Hirohisa Kyogoku
Visiting Scientist
Kohei Asai
Junior Research Associate
Kaori Hamada
Technical Staff II
Yuanzhuo Zhou
Student Trainee
Haruki Morioka
Student Trainee
MeiAkiko Mukose
Student Trainee
News
Sep. 12, 2022 Research
Smaller eggs enhance IVF outcomes for male infertility in mice
Nov. 26, 2021 Research
Successful fertilization requires careful coordination of chromosomes
Dec. 17, 2020 Research
Oh so simple: Eight genes enough to convert mouse stem cells into oocyte-like cells
Jul. 31, 2020 Research
Mice need kinetochores rich in a microtubule crosslinker to achieve error-free oocyte division
Jul. 20, 2018 Research
Mechanism identified that stabilizes chromosome pairs during meiosis