New research by Laura Landweber, PhD, who has joint appointments in the Department of Biochemistry and Molecular Biophysics, the Department of Systems Biology and the Department of Biological Sciences at Columbia University, is being featured by Columbia Univeristy Iriving Medical Center Newsroom.

As reported, a new study of a single-celled eukaryote with 16,000 tiny chromosomes may shed light on a recently discovered feature of the human genome.

Methyladenine, or 6mA—a modification of DNA common in Oxytricha trifallax—has only recently been found in multicellular organisms, with some studies suggesting a role in human disease and development.

Finding the enzymes that lay down the methyl marks will be critical to understanding what 6mA is doing in Oxytricha and other organisms, but the enzymes have been difficult to identify.

The new research—to be published in the June 13 issue of Cell—reveals how 6mA marks are made to the Oxytricha genome and suggests why the enzymes have been hard to find.

Read more about the Oxytricha genome and the Landweber lab’s new insights into 6mA and its potential role in human diseases.

Dr. Landweber has been studying Oxytricha for two decades and previously uncovered its 16,000 chromosomes. (See related Faculty Q+A and video.)

Systems Biology Graduate Brian Ji, PhD

For Brian Ji, the big draw to systems biology stemmed from his passion for applying quantitative approaches to understanding biology. While an undergraduate at the University of Wisconsin-Madison, Ji studied nuclear engineering and credits that training for the way in which he tackles scientific questions: creatively, and as a problem solver. 

“There is no one right approach to asking a question and setting out to answer it, and that freedom is what makes science fun for me,” he says. 

Ji studied under Dr. Dennis Vitkup in the Vitkup lab and completed his thesis defense for systems biology in the fall of 2018.  Also an MD student in Columbia’s Vagelos College of Physicians and Surgeons , Ji was attracted to Columbia because of the close interplay between the Systems Biology Department and the Columbia University Irving Medical Center. “Ultimately,” he says, “the opportunity to sit at the intersection between math, biology and medicine was too good to pass up.”

Ji’s PhD work focused on understanding spatiotemporal dynamics of human gut microbiota. He developed several frameworks that leveraged the increasing availability of high-throughput sequencing data to better understand and precisely quantify patterns of human gut microbiota variability across time and space. His work showed that characterizing dynamics—changes in bacterial abundances in our gut—are critical to understanding how these ecosystems function and is highly connected to multiple factors such as host diet, travel and diet. 

Ji also spent part of his PhD studying limitations of cancer cell growth in different environmental conditions. He credits Columbia for exposing him to a variety of research topics.