Long before the emergence of the coronavirus pandemic, the Yale Genome Editing Center (YGEC) was a valuable resource for preserving genetic data for important medical and biological research.
The center’s scientists genetically engineer research colonies, or “strains,” of mice with CRISPR-Cas9 technology and preserve their genetic information at key stages of experiments through cryogenetic freezing techniques. This enables a variety of Yale researchers to investigate intricate biochemical processes, disease pathways, and molecular interactions involving a host of medical conditions by helping them study animal models and preserving genetic “snapshots” of the results.
In the weeks since Yale paused all but the most critical lab-based scientific research as a public health measure, YGEC’s cryogenetic work has been operating at full tilt.
In 2019, YGEC preserved 135 research strains for the entire year, or about 2.5 projects per week on average; within just one week of Yale’s decision in March to close most labs, YGEC fielded at least 30 requests for help.
“It’s everything,” said Timothy Nottoli, the center’s co-director. “It’s cancer research, heart disease, diabetes, skin diseases, lung diseases, neurological development, basic developmental biology. It’s the full range of biological research going on at Yale.”
The rush wasn’t a surprise.
“We knew it was coming, so it wasn’t a scramble,” Nottoli said. “But it meant we needed to prioritize the cryopreservation work and effectively go into hibernation with some of the other projects we would have been doing.”
As a public health precaution, the center has reduced its laboratory staff from five people in the lab at one time to just one — or two, in the case of YGEC co-director Xiaojun Xing and his wife, YGEC associate research scientist Suxia Bai. While on duty, lab workers wear full personal protective gear to protect both the worker and the genetic material being preserved.
“We have completed 19 research strains since March 2 and another 20 strains within the next two weeks,” said Xing, who leads the lab’s cryopreservation work.
The strains are stored in tanks of liquid nitrogen that chill the material down to -320 degrees Fahrenheit. There are eight small tanks and two large tanks.
“We use an improved, patent-pending method for sperm cryopreservation,” Xing said. “With this method, the cooling rate — one of the key factors — is easily controlled to an ideal range, which guarantees that the majority of sperm survive the freezing and thawing process.”
Xing and Nottoli said the preservation and safeguarding of so many irreplaceable research colonies is vitally important for making sure Yale scientists can resume their work when it is safe to go back to their labs. Each research strain represents months or years of funding and work that may lead to breakthroughs in medical treatments and a better understanding of fundamental biological processes.
“I feel like we have a big responsibility,” Xing said. “It is the duty and responsibility of this center to finish this job.”
That timing is fortunate, Xing and Nottoli said, because another round of genome editing and cryopreservation is just around the corner for COVID-19 experiments.
“I’ve had a couple of inquiries already,” Nottoli said. “One of them has to do with looking at potential mutations in the lung response to the virus. Going forward, this will be a priority.”
