For as long as he can remember, Grant Jensen has been fascinated by cells.
Tiny cells form the basic structures of all living things — each with their own specialized function and operation. But getting a clear picture of a cell isn’t easy.
“Cells are messy. They are complex and difficult to understand,” said Jensen, dean of the College of Physical and Mathematical Sciences at BYU. “Advances in biology are usually punctuated by developments in microscopy. Every time a new or more powerful microscope is developed, we’re able to get a clearer view of what’s going on inside a cell.”
Prior to coming to BYU, Jensen was a professor of physics and biophysics and the director of the Caltech Cryo-electron microscopy (Cryo-EM) Center at the California Institute of Technology. It was there that he pioneered the field of electron cryotomography, an imaging technique used to produce 3D views of cells and viruses.
Now, thanks to the work of Jensen and his students, scientists are learning much more about the structure and function of cells. Some of his research, recently published in the academic journal Science, has produced more detailed images of a cell than ever seen before.
To capture such images, Jensen and his team genetically fused their target of interest to a fluorescent protein and then image a cell in a light microscope. The fluorescent proteins revealed where in the cell his target of interest was.
Jensen then froze the cell and placed it in an electron microscope to get a more detailed look. He further rotated the cell in the microscope to take pictures of it from different angles. These pictures were then merged to create a 3D reconstruction of the cell.
The images revealed thin tubes within the endoplasmic reticulum that hadn’t been observed before by scientists. Within the tubes, Jensen found a left-handed double helix — something he wasn’t expecting to see.
“This was one of the first times that anyone has been able to follow a fluorescent signal into a cell and see the structure the individual proteins formed,” said Jensen. “This hasn’t been possible before. We’ve never been able to get images like this within a cell when its structures are in a normal state. Cryo-EM allows us to freeze a cell and then look right at it like never before.”
Jensen says this opens the door to future research for scientists to explore other components of cells in greater detail, which will lead to new discoveries in medicine and treatment.
“It’s a tremendous advance to be able to simply look inside a cell and see what structures are there at the protein level,” he said.
Jensen loves the challenge of discovering new things. He’s grateful to live in a day in which God is “pouring down knowledge from heaven upon the heads of the Latter-day Saints.” He says that even though cells are complex and there are still more questions than answers, “God is letting us discover amazing things about how the world works in these modern days.”
This research was conducted at the Jensen Lab at Caltech, where Jensen has continued to oversee the research of students there until they graduate. Jensen is also an author of the online textbook The Atlas of Bacterial & Archaeal Cell Structure.
