Naoko Irie: Encounters with People, Encounters with Humans

From 2011 to 2023, I worked on research regarding the development of human germ cells (eggs and sperm) at the Gurdon Institute, University of Cambridge, UK, under the guidance of Professor Azim Surani. It was a long stay, but every time I look back on its beginning, I feel that encounters are truly mysterious things.

Prior to 2011, I was researching bone metabolism homeostasis using mouse models at the Keio University Graduate School of Medicine. After obtaining my PhD, my desire to solve the mysteries of germ cells—the very foundation of life—grew stronger. Despite having no track record or connections, I suddenly sent an email to Professor Surani, a leading figure in germ cell research. Of course, there was no reply. After sending several reminders, I received a response saying, "It is difficult because there is no space in the laboratory." I immediately replied with a half-joking, half-serious message: "I am not big, so I don't need much research space!"

After this "unconventional" exchange, I was fortunate enough to dive into germ cell research. Perhaps because of how it started, my research theme also headed in a direction that was "not the mainstream" at the time. Back then, mammalian germ cell research was dominated by mouse models, and everyone in the lab was focused on mice. In that environment, I started research from scratch using human ES cells and human samples—which I had never handled before—and was able to lead it to several important discoveries. This episode is still passed down inside and outside the laboratory as the "most rare and amusing story."

After returning to Japan, I worked at CIEA (Central Institute for Experimental Animals), and since April last year, I have been leading a laboratory at the Keio University School of Medicine Department of Molecular Biology. This has increased my opportunities to be involved in recruiting members. During this process, I sometimes wonder, "Why did Professor Surani decide to welcome me into his lab?" When I met the professor, who received the 2025 Kyoto Prize, and timidly asked him, he jokingly replied, "When I first met you at a conference in Japan, I did think you looked like you would fit in the space." I also recall him saying, "Recruitment is intuition."

While cherishing the many precious encounters I have had with people and humans (cells) so far, I look forward to new encounters in the future and intend to devote myself to my studies.