Alum’s Work Helps Fill in Gaps in the Human Genome

When Gabrielle Hartley ’17 was a kid, she loved to read Nancy Drew and Encyclopedia Brown mysteries. Naturally curious and interested in figuring things out, she has entered a field of science that enables her to solve puzzles much like Nancy Drew, but Hartley does her work in the laboratory, exploring the human genome.

A candidate in the molecular and cell biology doctorate program at the University of Connecticut, Hartley likens studying the human genome to “the grownup version” of the books she enjoyed as a child, since so much has yet to be discovered about how human DNA works.

As part of the Telomere-to-Telomere (meaning one end of a chromosome to the other) Consortium, Hartley helped characterize repeat sequences missing from the human genome. She and her teammates worked together to solve a puzzle – one that was particularly challenging because the pieces all look the same.

“There’s a correct way to put it together, but it’s impossible to know which way is right,” explains Hartley. “Technology now allows those pieces to be bigger, so these repetitive regions were able to be put together for the first time.”

‘How scientists can use their respective expertise’

As they worked together to solve the puzzle, Hartley and her teammates paid attention to the repeats and where they were in the genome. More new sequences added to the genome meant they discovered dozens of repetitive sequences that had not been characterized before.

Earlier this year, she wrote for The Conversation, a nonprofit news organization, about how they filled in gaps in the human genome. She’s grateful for the opportunity to have been part of such meaningful research that promises to further scientists’ understanding of the human genome.

“It was incredible to be a part of such an impactful project,” she said. “I think the process has been equally important to what the group was able to accomplish. Our team was hugely collaborative, with more than 25 people working on the repeats with us, both in the U.S. and internationally. It was an amazing example of how scientists can use their respective expertise to further collective, open science.”

‘The better we’ll understand how our genomes work’

Studying repetitive DNA is promising to scientists in myriad fields, such as forensic science and epidemiologists. Long considered the genome’s “junk” because its purpose was not widely understood, scientists are now understanding repetitive DNA’s importance.

Repetitive DNA, explains Hartley, can go a long way to explaining variation between individuals’ DNA. That makes it particularly useful for forensic scientists when making DNA identifications. Because it can affect genes, it can also play an important role in genetic disorders, such as Huntington’s disease. It also has the potential to provide countless other clues to scientists who are exploring the genome.

“One of the most fundamental concepts you learn in molecular biology is that DNA ultimately codes for proteins, which do all kinds of important things in the body – but most repetitive DNA doesn’t make a protein,” explains Hartley. “Repeats are also really important to cell regulation and can even contribute to how species evolve. The more we understand about them, the better we’ll understand how our genomes work.”

‘You can let your interests guide you’

Hartley, who earned bachelor’s degrees in biology and forensic science from the University of New Haven, says her time as a Charger offered her many opportunities to explore. Studying abroad at the University’s campus in Prato, Italy, and taking service-learning courses, which helped cultivate her interest in nonprofit work, were particularly meaningful, she says. While gaining hands-on experience in the lab, she built the foundation for much of the research she is now doing as a Ph.D. candidate.

“I had amazing mentors at the University of New Haven, both in the Biology and Forensic Science Departments,” she said. “It was so important to see wholehearted scientists, especially women, who modelled what it meant to ask the right questions and be confident in one’s own abilities as a scientist. I always felt encouraged to learn by trying something out, which is so important in research.”

As part of her dissertation, Hartley is studying the genomes of gibbons, endangered apes native to southeast Asia, she describes as “interesting and funny” animals. Because their chromosomes have a great deal of rearrangement and their genomes are evolving particularly quickly, she is exploring why some genomes tend to shuffle while others remain more stable.

While working on her doctorate, Hartley also completed a graduate program in nonprofit management, further exploring her passion for nonprofit work. She hopes to bring together her passions for genomics and nonprofit work during her career.

“One thing I really love about research is that you can let your interests guide you,” she said. “There are so many things that we don’t even realize are informed by genomics, from human medicine to species conservation.”