Ai Kiyomitsu

Research Scientist
Food Science and Biotechnology

My Background

I received a Bachelor’s and Master’s and Doctorate (2007) degree in Agriculture from Kyoto University. I continued on at Kyoto University as a Postdoctoral Fellow in two different laboratories: Nutrition Chemistry (2007-2013) and Fermentation Physiology and Applied Microbiology (2012). After a parenting period, I began a new research project using Medaka fish with Assistant Prof. Tomomi Kiyomitsu at Nagoya University (2019). From April 2020, I joined OIST to continue my work with Medaka in collaboration with Cell Division Dynamics (Kiyomitsu) Unit.

Project

I am interested in:

  1. How Medaka early embryos generate beautiful cellular patterning to achieve proper development (see Figures below).
  2. How environmental stress affects this process at the molecular level.

To understand these questions, I am currently establishing several transgenic Medaka using CRISPR/Cas-mediated genome editing. I will use live cell imaging to visualize key molecular players in the early cell division process and analyze phenotypes in response to their depletion or inhibition. I will also analyze how environmental stress affects their behavior and function. 

Medaka embryo

Publications

2026
Balanced RCC1 activity organizes the specialized spindle midplane during cleavage divisions

Ming Y, Kiyomitsu ATakahashi Y, Kiyomitsu T.
bioRxiv: August 2026
https://www.biorxiv.org/content/10.64898/2026.08.18.745458v1

KIFC1 overexpression induces monopolar spindles by preventing centrosome separation during rapid cleavage divisions
Yamamoto T, Kiyomitsu AMing Y, Kiyomitsu T.
bioRxiv: August 2026
https://www.biorxiv.org/content/10.64898/2026.08.14.744973v1

Local fluidization of an active cytoplasmic gel partitions large cells
Bai L, Field C, Kiyomitsu A, Shen Y, Orlovsky N, Kiyomitsu T, Mitchison T.
bioRxiv: August 2026
https://www.biorxiv.org/content/10.64898/2026.08.11.744254v1

Spatiotemporal organization of dynein in bulk cytoplasm promotes aster growth and positioning in large embryos
Kiyomitsu A, Bai L, Mitchison T, Kiyomitsu T.
bioRxiv: April 2026

2024
Ran-GTP assembles a specialized spindle structure for accurate chromosome segregation in medaka early embryos
Kiyomitsu A, Nishimura T, Hwang SJ, Ansai S, Kanemaki MT, Tanaka M, Kiyomitsu T. 
Nature Communications 2024 Feb 1;15(1):981. doi: 10.1038/s41467-024-45251-w
https://www.nature.com/articles/s41467-024-45251-w

2023
Ran-GTP assembles a specialized spindle structure for accurate chromosome segregation in medaka early embryos
Kiyomitsu A, Nishimura T, Hwang SJ, Ansai S, Kanemaki MT, Tanaka M, Kiyomitsu T.
bioRxiv: July 2023
https://biorxiv.org/cgi/content/short/2023.07.20.549960v1

Award

2024 NIKON JOICO AWARD
Kiyomitsu T and Kiyomitsu A

Annuual Report

Annual Report FY25
Annual Report FY24
Annual Report FY23
Annual Report FY22
Annual Report FY21
Annual Report FY20