International Education Week DNA project traces genetic ancestry
The process to collect a sample for mitochondrial DNA (mtDNA) testing is rather involved, with a number of precise steps that, if carried out incorrectly, can render the sample unusable. But last month, Dr. Jon Coren, associate professor of biology, assisted two dozen students and faculty and staff members as they walked through the process—from swirling saline solution inside the mouth to generating ample quantities of a mitochondrial DNA fragment for testing.
This exploration into one means of determining genetic heritage was part of last week’s International Education Week at Elizabethtown College. The event, which celebrates the benefit of international education and exchange through a variety of programs across campus, is a way of showing the educational value of diversity. Kristi Syrdahl, director of international student services, said that inclusion of the DNA program was an idea two years in the making, following her attendance at the Martin Luther King Jr. Memorial dedication in Washington, D.C. “The event was attended by nearly 10,000 people from all walks of life, ages, abilities and racial/ethnic backgrounds,” she said.” It was, perhaps, the most diverse crowd I had ever been in and I was moved beyond words.”
We are all part of the human race, and if there was a way to really look at that, to look at our commonalities, then that could be a really powerful teachable moment.”
Not only was she emotionally affected, she also was inspired to do something to create awareness of human interconnectedness—the similarities rather than differences—at Elizabethtown. “I kept thinking: We are all part of the human race, and if there was a way to really look at that, to look at our commonalities, then that could be a really powerful teachable moment,” she said.
Though the concept didn’t gel for that year’s academic programming, Syrdahl and Coren held steady in their interest to include it as part of International Education Week. On Oct. 17 of this year, 25 participants gathered in a classroom in Lyet to start the process of tracing part of their genetic ancestry.
Each participant procured his or her own DNA from cheek cells to send to GENEWIZ, a genomics service company, for sequencing. The information from the samples was then placed in a database at Dolan DNA Learning Center, the educational component of Cold Spring Harbor (N.Y.) Labs. “Some samples were not viable,” Coren said. And, at the lab, several more were found to have DNA sequencing that was not high enough quality. “Seventeen of the 24 samples that were produced in the laboratory generated valuable information.”
Three weeks later, in Gibble Auditorium, Coren presented “Where Do We Come From?: Tracing Genetic Heritage through Mitochondrial DNA,” as part of International Education Week. He explained the process of procuring the cells and testing, the value of tracing mtDNA and the significance of the outcome. In the audience, eager test participants listened as Coren described the role that mitochondrial DNA plays in determining genetic ancestry. Afterward he shared a link to the testing lab so each person could, on his or her own time, research personal results, comparing genetic information to others in the group, as well comparing to non-human mtDNA, the mtDNA of ancient humans and modern humans, and other groups on file at the laboratory.
“All cells have organelles that do various things,” Coren said. “The mitochondria’s main function is to generate provide energy in all of your cells. If the mitochondria malfunction, tissues and organs with high energy demands can be damaged, causing various genetic disorders and even death.” Mitochondria also carry genetic information that is inherited through matrilineal descent—passed down from the mother to her offspring. Her daughters pass their mitochondria along to their children, but the sons do not. Therefore, Coren cautioned, any information on genetic heritage found in mtDNA tells only part of the genetic history. “You need to take the results with a grain of salt,” he said. “It’s only a small part of the picture.”
Ancestral information also is carried through the Y chromosome—from father to son—and the other chromosomes. “Not so long ago obtaining your genetic information was not financially feasible,” Coren said. “In a couple years this information will be available, inexpensively, to everyone, including information on genetic disorders.”
The purpose of this month’s program, however, was to explore ancestral differences and similarities. “I couldn’t shake the idea that regardless of what way we define ourselves, what regions of the world we come from, we all come from a common ancestral ‘Eve’,” said Syrdahl, recalling a research project she’d completed as a master’s candidate at NYU when she conducted research in Puerto Rico on ethnic and racial/groups across the island. She was amazed at how much common mitochondrial DNA seemingly divergent groups shared.
Coren agreed. “The person you think is so different might be more closely related than you realize.”
Within the biological sciences it is widely believed that modern humans evolved from ancestors who originally lived in Africa. From there, the groups dispersed across the globe, creating the diverse population we presently have on earth. If a person’s mtDNA is a perfect match with someone else’s mtDNA, there is a good chance that the results indicate shared ancestry; similar mtDNA comparisons show long-ago geographic ancestry.
“From my perspective, the purpose of doing the testing was to start build bridges between peoples of seemingly divergent backgrounds from a place of irrefutable evidence,” Syrdahl said. If we understand our commonalities, she said, “we could move forward in a more peaceful and understanding direction, which circles back to the messages of MLK Jr.”