The Cornell University College of Veterinary Medicine (CVM) has recently welcomed many new faculty members to our academic departments, each one bringing a unique set of skills and experience that enriches our college every day. In this Q&A series, you'll get to know their interests, expertise and more.

Dr. Jongmin Kim, assistant professor, Department of Biomedical Sciences

Q: What has been your path leading up to Cornell?

I studied biology as an undergraduate in Korea and came to the United States as a graduate student. 

I did my Ph.D. at Stanford University with Dr. Minx Fuller. In Minx's lab, I worked on a protein that blocks aberrant expression of inappropriate genes during fly spermatogenesis. I learned the basics of genetics, genomics and developmental biology. 

After my Ph.D., I did my postdoctoral training at Massachusetts General Hospital with Dr. Bob Kingston. Using mouse genetics, I worked on a chromatin modifier called Polycomb Repressive Complex 1 (PRC1). I investigated how PRC1 changes its composition and character as sperm precursor cells differentiate and how it blocks unwanted gene expression to guide spermatogenesis. 

I am thrilled to launch my independent research program at Cornell with many scientists whose work I respect as colleagues.

Q-What drew you to CVM?

Cornell Vet has a strong reproductive biology program. One of my mentors described it to me as, “You can be an unapologetic germ cell biologist there.” In other words, my mentor tried to tell me that this is a place where there is an appreciation of reproduction as an important scientific problem. Based on the scientific exchanges through attending colleagues' lab meetings or corridor chats on scientific problems, I know made the right decision to come here. 

Q-What is your area of expertise?

I work on chromatin-modifying proteins and their function in gene regulation. My models are germ cells in spermatogenesis in flies and mice. Our methodologies are primarily genetic perturbations: making mutations or expressing different versions of the proteins we study. We use various read-out methods -- microscopy, biochemistry, and genomics to evaluate the consequences of those genetic perturbations. As I have worked on often rare cell types from the testis, I have experience in genomic profiling and analysis methods, using a small number of cells. 

Q-What drew you into this area?

I was broadly interested in development and cell fate determination, but my path here sometimes involved stochastic choices. I joined my graduate advisor, Dr. Minx Fuller's lab, because I was interested in asymmetric stem cell divisions. There, I did a genetic screen using fly spermatogenesis as a model. One of the genes I identified turned out to be a transcriptional repressor. Since then, I have been studying the mechanism of gene silencing regulating male germ cell fate.

Because I studied the repressor protein, I wanted to build my expertise in studying the molecular mechanisms of these chromatin-modifying proteins. So, I joined the lab of Dr. Bob Kingston at Massachusetts General Hospital as a postdoctoral fellow. Bob's lab was known for chromatin biochemistry, purifying these chromatin-modifying proteins, and testing their activities in the test tubes. But instead of doing biochemistry, I observed a spermatogenesis defect in the mouse mutant for one of the genes the lab studied. I ended up working on chromatin regulation in mouse spermatogenesis. 

So, while there is an element of chance to my path, the theme of gene silencing mechanisms in spermatogenesis ties together my scientific experiences. I want to emphasize that there were many mentors I could talk to at every step to get advice on my path. Collectively, they helped to steer me to where I am today.

Q-What about your professional work are you most proud of?

My advisor and I named a gene. During graduate school, I did a genetic screen in fruit flies and identified a previously uncharacterized gene. This gene was required to block the misexpression of somatic (e.g., genes expressed in the brain or gut) genes in the testes. Therefore, we named it Kumgang, which is a name for the mythological guardian in front of temples in Asian countries, as a guardian of germ cell fate. I am still investigating how Kumgang blocks misexpression and how Kumgang-like proteins function in other tissue types and species.

Q-What impacts or applications do you hope to see your work have?

Gene silencing mechanisms, regulated by proteins like Kumgang, are not only important for spermatogenesis, but also for other processes, such as aging and tumorigenesis. For example, when gene silencing pathways are defective, oncogenes can be aberrantly activated, and that event can drive uncontrolled proliferation of those cells. Thus, understanding the basic mechanisms of transcriptional fidelity will have a broad impact on age-related disease processes like cancer and its more immediate connection to male fertility and spermatogenesis. 

Q-What’s something most people don’t know about you?

At one point during my (mandatory) army service in South Korea, I was an aide to a four-star general. I was very good at ironing shirts at the time. Alas, not anymore.

Q-What’s the best part of your job?

When you do research, sometimes you realize that you are the first person in the world to observe something or answer to a question. It doesn't have to be a groundbreaking discovery. By developing an antibody, you get to be the only person in the world who has seen where that protein is localized in the cell. By making a mutation in a protein residue, you are the first to know whether that residue is important for the biological processes you are interested in. These are rare but incredibly exciting moments. 

As I progressed in my career, I realized that teaching and mentoring became a more important part of my job. Helping students become better scientists is very rewarding. Sitting in the lab meeting of students I mentor and seeing them confidently answering questions brings you a special kind of happiness. Plus, exciting discoveries are rare, but you get to help and mentor students every day.

Q-What’s the most challenging part?

There are significant uncertainties in pursuing a career as a scientist. Often, it seems like there is no correlation between your effort and outcome. Most of us have experienced a period of no results despite working hard on a problem. Even when things go well, there is no guarantee that one can obtain an independent scientist position or sustain a research career by continuously securing research grants.

One thing I try to remember is that 'somehow' things work out if you put in an honest effort. Of course, there is no guarantee. But I think some small dose of blind optimism and having a long-term view helps me maintain motivation and be a happy scientist.

Q-What are the benefits of working at CVM? At Cornell?

Supportive and collegial environment. Starting as a new professor and building a new research group is not easy. I did not realize how important the department and school environment was. I appreciate everyone in the BMS department and CVM generously sharing their time to help and mentor me. I thank everyone who invited me to their lab meetings, went to coffee or lunch to answer my numerous questions, and picked up my new microscope with me when the truck dropped off a massive box without any notice.

I look forward to working with the CVM and the larger Cornell community, exchanging ideas, and collaborating on experiments.