Q&A: How Do the Same Genes Make Different Humans?

by AMNH on


This Wednesday, Tuuli Lappalainen, a researcher at the New York Genome Center and assistant professor at Columbia University, will discuss how genes are turned “on” or “off” and how their activity levels help explain variation in human beings, including varying risk of developing diseases.

Lappalainen Portrait

She recently answered a few question about her work, how she became interested in the field, and what motivates her research.

The human genome has been sequenced for more than a decade now. So what are the big questions in the field of genetics today?

The biggest questions are, how does the genome function to give rise to living individuals? And also, how does it result in individuals with different physical characteristics, disease risks, and other variations?

You mentioned disease risk. What are some of the diseases that are associated with genetic regulation, in other words, how high or low a gene is tuned? 

A lot of common complex diseases, from cardiovascular disease to schizophrenia, are associated with genetic markers. In all of those diseases, research shows us that genetic regulation is a factor.

What are some reasons the same gene might work differently in different people?

Variation is pervasive in the genome, and almost all genes have a regulator gene that controls how active they are. We’ve gotten really good at finding these regulators and variations, which means we have a huge haystack of things to sort through as we work to find things that are connected to disease risk.

What factors can turn a gene on or off? 

Basically everything. If you think about the environment from a genome perspective, it faces multiple different factors, like what kind of cell it is. Whether you’re a liver or skin or neuron cell is going to affect gene expression, for example. Then, you have aspects of the external environment, like whether you had flu a few weeks ago, which can affect gene expression. Some cell types are built to adapt to these changes, but others are less adaptable.

What drew you to this field of research?

From my teen years, I was fascinated with biology and evolution. It’s a very cool field with a lot of new opportunities and new technology that lets us do things that were impossible until a short while ago. It’s also a place where there’s a real possibility of making an impact in human health. I’m not a medical doctor, but if some of my work can help to improve people’s health, that’s a real motivation for me.

To learn more about Dr. Lappalainen's work, check out her SciCafe presentation on Wednesday, June 3, at 7 pm in the Wallach Orientation Center.