A Synchronized Population | Yasuhiro Naito, Assistant to the Dean / Professor, Faculty of Environment and Information Studies
2021.06.01
There is a microorganism called Caulobacter crescentus . It inhabits freshwater lakes and other relatively nutrient-poor environments and has been heavily utilized by life scientists for cell cycle research since the 1970s.
The cell cycle is the process from when a cell is born through cell division until it divides into two new daughter cells. During one round of the cell cycle, a cell doubles nearly all of its biological molecules, such as proteins and DNA, skillfully partitions them, and finally divides into two. This mechanism of self-replication and proliferation through a controlled cell cycle is one of the most fundamental and important functions for the survival of organisms as a population.
Whether in nature or in a laboratory test tube, each cell progresses through its cell cycle at its own pace. A population of hundreds of millions of cells or more is a mixture of cells at various stages: some are busy making materials for the next generation, some are on the verge of dividing into two, and others are living quietly with no immediate plans to divide. Consequently, if life scientists half a century ago wanted to know what happens just before or after a cell divides, it was very difficult for them to collect only the cells that were about to divide (today, sorting them is considerably easier).
A mutant strain of *Caulobacter crescentus*, isolated in a lab at the University of Washington in the late 1970s, had the characteristic of allowing for the easy collection of "synchronized" cells, all at the same stage of the cell cycle. Numerous unique research findings were produced using this mutant strain, named "NA1000." As a graduate student in the 1990s, I was deeply impressed that such a fascinating creature existed and that there were equally fascinating scientists who discovered and utilized it.
A collection of individual organisms is called a population. In a population where the timing of generational turnover through cell division or reproduction is staggered and "asynchronous," change is generally gradual. At any given moment, a certain percentage of cells are about to divide, while another percentage is preparing to divide or is resting. The population's generational turnover proceeds constantly, partially, and little by little. The generational turnover of human populations is also "asynchronous." The individuals and families that make up populations like towns, villages, and nations undergo generational change gradually. In contrast, in a population with synchronized proliferation, many cells divide simultaneously, causing a rapid, wholesale generational turnover. The previous generation exits all at once, and the new generation suddenly comes to dominate the population.
When SFC was established 31 years ago, it began in a "synchronized" state, with all faculty members joining at once as first-year "newcomers" to the Faculty of Policy Management and the Faculty of Environment and Information Studies. Of course, there was diversity in age, ranging from veterans who had already built careers in other faculties, universities, or companies to the youngest group of faculty members who joined shortly after obtaining their degrees. However, compared to the older faculties that were well over 100 years old and had undergone numerous generational changes, SFC could be described as a highly "synchronized" population. And they were the one and only "founding population" who personally experienced and shared the "beginning" and "origin" of SFC.
Likening my esteemed senior colleagues to a population of microorganisms might earn me scolding from various quarters, but ever since I joined as a contract research associate in 2000, I have thought of *Caulobacter crescentus* and felt that SFC was a special population where the faculty's status was reasonably synchronized. I have often put on a scientist's lens to observe it with great interest.
Admittedly, the "individuals" making up the population were far from self-replicating copies; they were excessively unique and different. Nevertheless, from the perspective of an "outsider" like me who slipped in ten years after its founding, there were many moments when I felt, "They really are synchronized." A "synchronized" population shares something solid, and I enjoyed gradually getting to know what that was, albeit belatedly.
The "individuals" of that first generation, who constituted the initial population, are now almost completely disappearing after 30 years. This is not a matter of whether that is good or bad. The fact is that the first, inevitable generational turnover of the "founding population" that began in "synchrony" 30 years ago is now proceeding on schedule and is on the verge of completion. The SFC faculty population will continue to undergo generational changes, from the second to the third generation and beyond. However, such a distinct generational turnover will likely be the first and the last.
Something new may be budding, and something may be lost. Personally, I believe we should not uncritically revere the past; we should act as we see fit, even if we stumble. But if I could wish for one thing, it would be that we continue to share the aspiration to keep crossing the boundaries of academic disciplines. Simply gathering faculty from diverse fields does not create such boundary crossing. Unless we find each other interesting, try to understand one another, strive for empathy, and have the resolve to change ourselves, we will not merge. I hope SFC continues to be not a well-behaved place where diverse academic fields are neatly compartmentalized like a Shokado bento box, but rather something more like a mysterious yaminabe hot pot. As for whether uninhibited boundary crossing is currently being achieved at SFC, I feel we are still halfway there, or perhaps not even that far. Yet, it is also a fact that I have met many colleagues and students who are willing to cross boundaries, even at their own expense.
About 15 years ago, after working at SFC on contract and fixed-term appointments, I applied for a tenured position. The final step of the review was an interview where I was surrounded in a U-shape by about 15 senior faculty members—a scene that could have illustrated the entry for "high-pressure interview" in a dictionary. There, after I had freely and extensively expounded on my ideas about the life sciences, one of the faculty members surrounding me asked, "You keep going on and on about science, but isn't it possible for something to be academic without being science?" I have no memory of how I answered, but the question itself has remained in the back of my mind, and I still think about it from time to time.
A faculty, a campus, that would ask "Isn't it possible for something to be academic without being science?" in an interview to decide whether to hire someone like me for a tenured position—someone who studied at a regional medical college, left the medical sciences midway through graduate school to pursue microbial molecular genetics, and then moved to SFC to switch to computational biology, a person who "seems to have wandered through various fields but has in fact only ever scurried about within the palm of the natural sciences (especially the life sciences)"—is surely a rarity, not just in Japan, but in the entire world.
I thought from the bottom of my heart, "SFC is truly fascinating," and that feeling hasn't changed. Being interesting doesn't automatically mean being high-quality, and I often encounter situations where what seems interesting is actually a weakness. But it is, without a doubt, interesting. The crucial thing is how we recognize that interestingness and where we direct it.
As the faculty who formed the first-generation founding population depart, SFC is now undergoing a drastic generational turnover, the likes of which will probably never be seen again. As a member of this community, while doing what I can in my own way, I want to continue observing this delightful "population that is breaking out of synchrony" through a scientist's lens for the next ten-plus years until my retirement, just as I have for the past twenty.
I am grateful for the invitation to contribute to "Okashira Nikki" for a second time. It has been a good opportunity to recall and organize the many conversations I have had with colleagues and students over the past twenty-plus years.