Fall/Winter 2020 /The New (Ab)Normal/

CRISPR on Campus

Pomona students are already using the gene-editing technique discovered by 2020 Nobel laureate Jennifer Doudna ’85.

 CRISPR/Cas9 gene-editing techniques

The Prize

Jennifer Doudna ’85 wins the 2020 Nobel Prize in chemistry.

How CRISPR-Cas9 Works

The CRISPR-Cas9 genetic scissors consists of two parts: a short piece of RNA (a molecule that can read the genetic information in a cell’s DNA) and an enzyme (a protein that acts as a biological catalyst, causing or speeding up a chemical reaction in a cell). The RNA contains a “guide” sequence that binds to a specific target area on the strand of DNA. The enzyme, known as Cas9, then cuts the DNA at the designated location. Once the DNA has been cut, the cell’s own natural repair machinery goes into action. Researchers can use that repair process to add, delete, replace or deactivate pieces of genetic material at that precise spot, resulting in a rewritten section of DNA code.

Decades after 2020 Nobel Prize winner Jennifer Doudna ’85 roamed the halls of Seaver North or paused under a sycamore on Marston Quad, Pomona College students working in campus labs use the CRISPR/Cas9 gene-editing techniques she has pioneered.

They’ve worked with CRISPR on such organisms as the tiny worm C. elegans, the fruit fly Drosophila melanogaster and the brewer’s yeast S. cerevisiae as they conducted research in the labs of molecular biology professors Sara Olson, Cris Cheney and Tina Negritto or in the neuroscience labs of professors Karl Johnson and Elizabeth Glater.

Though revolutionary, CRISPR doesn’t involve a lot of expensive equipment. Mainly, it is nature’s own—what the Nobel committee called “one of gene technology’s sharpest tools: the CRISPR/Cas9 genetic scissors.”

The fact that undergraduates can use it “speaks to just how amazing and accessible CRISPR is as a tool,” says Ellen Wang ’20, who worked in Cheney’s lab as a student and is now a post-bac researcher at the Buck Institute in Northern California as she prepares to apply to M.D./Ph.D. programs. “Generally, how it works is that it uses an enzyme from bacteria, and this particular enzyme can basically just cut out or edit parts of the genome. I think CRISPR to a non-science person is probably super crazy to think about, like something straight out of science fiction, right? The fact that you’re just able to edit genes? But in reality, in the molecular biology field, it’s actually a super common technique now. People use it to figure out what certain genes do. For example, someone can use CRISPR to delete a certain gene and see what effects it has on their model organism.”

Like any experiment, attempts to use CRISPR don’t always succeed. But Giselle De La Torre Pinedo ’19, who remained at Pomona for an additional year to work as a post-bac researcher in Olson’s lab, had great success as she helped implement the CRISPR-based lab Olson uses in her Advanced Cell Biology course.

“We must have made about 20 worm strains in the year that I was there,” says De La Torre Pinedo, now a Ph.D. student at Baylor College of Medicine in Houston. “We had a bunch of genes that we wanted to look at and to characterize a little more—genes that we didn’t know anything about. We took CRISPR and added some fluorescent proteins to all of those. And we also used CRISPR to get rid of those proteins and to get rid of parts of those proteins.”

An Example for New Generations

Doudna has become an inspiration to many Pomona students. De La Torre Pinedo was studying abroad at University College London her junior year when classmate Gurkaran Singh ’19 told her he was going to hear a certain Pomona alumna speak at King’s College.

“It was super cool,” De La Torre Pinedo says. “Afterwards people were going up to talk to her, but we were able to have a special little interaction because we were Pomona students. So we took a picture with the Cecil.”

Other ties endure. Fred Grieman, the Roscoe Moss Professor of Chemistry, came to Pomona in 1982 when Doudna was a student. They played on the Chemistry Department’s intramural softball team together—“She played second base and I played first,” he says—and now he tells his current students about her.

“You know, she was a really good student, but she wasn’t like, ‘Oh, that one’s going to win the Nobel Prize, and the rest of you aren’t,’” he tells them. “Many, many of our students are really good students, and she was one that was a really good student. So this could happen to them as well, or at least they could be doing that level of work. That’s an exciting thing for them to contemplate.”

It also might be comforting that even a future Nobel winner did not sail through all her coursework, says Grieman, who taught Doudna in physical chemistry.

“She had her difficulties with the material too, but she was the type of person that would just work through it and—you could tell—just loved working through that kind of stuff,” he says. “It was that kind of realization that if you find this joy in whatever work it is that you do, it just propels you to go to greater lengths that can lead to things like this.”

Pomona professors also carry Doudna’s legacy into the community. Grieman and Chemistry Professor Jane Liu have spoken to a local retirement group about Doudna and CRISPR. Olson has even taken the knowledge to area high school students through the Draper Center’s PAYS program (Pomona College Academy for Youth Success).

“It’s accessible technology for all ranges of students, not only undergrads,” Olson says.

Research on Campus and Beyond

Pomona students write senior theses incorporating CRISPR, including the recent work of Norani Abilo ’20 and Julián Prieto ’20 on vitelline-layer proteins within the C. elegans eggshell at fertilization. Several of Johnson’s neuroscience students have made CRISPR a central part of their thesis work, most recently using the technique to knock out a family of genes in the fruit fly responsible for synthesizing a sugar called chondroitin sulfate that is important for nervous system development and regeneration. And Christopher Song ‘16 used CRISPR to remove a gene involved in olfactory behavior from C. elegans for his neuroscience senior thesis in Glater’s lab. Among current students, Nikita Kormshchikov ’23 undertook a research project related to CRISPR last summer as part of RAISE, the funded independent research program that has replaced on-campus research during the pandemic.

As students go forth after graduating, some are finding their experience and awareness of CRISPR to be a major positive.

“It was cool because in my interviews for grad school, that was one of the things that came up,” De La Torre Pinedo says. “A lot of them were really excited that I had experience doing CRISPR because for a lot of the labs, it’s still fairly new.”

Just as important, De La Torre Pinedo says, she takes inspiration from Doudna as a woman. Being a female role model is something Doudna is aware of, as she noted in her remarks during her UC Berkeley news conference the day of the Nobel announcement. The award marked the first time two women have shared the Nobel Prize in chemistry.

“I think it’s great for especially younger women to see this and to see that women’s work can be recognized as much as men’s,” Doudna said that morning. “I think for many women, there’s a feeling that no matter what they do, their work will never be recognized as it might be if they were men. And I’d like to see that change, of course. And I think this is a step in the right direction.”

It was around the time she met Doudna in London, De La Torre Pinedo says, that she realized her calling might be research.

“For the longest time, I wanted to be a doctor,” she says. “I come from a pretty traditional Mexican household, and I moved to the States when I was 6, low-income, all that stuff. It was an ‘if you’re interested in science, you’re gonna be a doctor’ kind of mentality, because that’s going to get you the money and get you ahead in life.

“But then realizing more about all the options and doing research and then seeing powerful women like Doudna up there, doing crazy things—revolutionary, science-changing things—it was ‘Oh, we can do all of these things.’ That was definitely a moment where I had a chance to take a step back and tell myself that just because everyone was telling me that I should be a doctor, there are actually other ways that I could really contribute to the scientific world. And hopefully maybe have as big an impact one day, with whatever research I end up doing.”