Researchers find 'internal clock' within live human cells

September 11, 2017, New York University
Human cell nuclei with fluorescently labeled chromatin (purple) and nuclear envelope (green). Credit: Fang-Yi Chu and Alexandra Zidovska, Department of Physics, New York University.

A team of scientists has revealed an internal clock within live human cells, a finding that creates new opportunities for understanding the building blocks of life and the onset of disease.

"Previously, a precise point of a cell in its life could only be determined by studying dead ," explains Alexandra Zidovska, an assistant professor of physics at New York University and the senior author of research, which appears in the latest issue of the journal Proceedings of the National Academy of Sciences (PNAS). "However, with this discovery, which shows that the nucleus exhibits rapid fluctuations that decrease during the of the cell, we can enhance our knowledge of both healthy and diseased human cells."

The study, which also included Fang-Yi Chu, an NYU doctoral candidate, and Shannon Haley, an NYU undergraduate, sought to expand our understanding of the cell nucleus during the cell cycle.

It's long been established that the shape and size of the cell nucleus change dramatically during a cell's life. Unknown, however, was whether or not the nucleus changes its shape over short periods of time. This was largely due to technical limitations of carrying out such measurements in living cells.

To capture this dynamic, the scientists used a state-of-the-art fluorescent microscope that enables them to see extremely small and very fast shape changes of the cell nucleus in living cells.

The researchers discovered that the human has a previously undetected type of motion: its nuclear envelope flickers, or fluctuates, over a period of a few seconds. Notably, the amplitude of these changes in shape decreases over time during the cell cycle. Moreover, this motion marks the first physical feature that systematically changes with the cell cycle.

"Therefore, this process can serve as an of the cell, telling you at what stage in the the cell is," explains Zidovska. "We know that structural and functional errors of the nuclear envelope lead to a large number of developmental and inherited disorders, such as cardiomyopathy, muscular dystrophy, and cancer. Illuminating the mechanics of nuclear shape fluctuations might contribute to efforts to understand the in health and disease."

Explore further: Chromosome mechanics guide nuclear assembly

More information: Fang-Yi Chu el al., "On the origin of shape fluctuations of the cell nucleus," PNAS (2017). www.pnas.org/cgi/doi/10.1073/pnas.1702226114

Related Stories

Chromosome mechanics guide nuclear assembly

August 28, 2017

Every one of our cells stores its genome within the nucleus – the quintessential subcellular structure that distinguishes eukaryotic cells from bacteria. When animal cells divide, they disassemble their nucleus, releasing ...

Spectrin proteins spring into action to restore nucleus

June 20, 2017

When you lift weights, carry heavy boxes, or engage in physical activity, the cells in your body stretch and deform to accommodate your movements. But how do your cells recover, or return to their original state, once you ...

Study reveals how HIV enters cell nucleus

June 21, 2016

Loyola University Chicago scientists have solved a mystery that has long baffled HIV researchers: How does HIV manage to enter the nucleus of immune system cells?

Recommended for you

Integrating optical components into existing chip designs

April 19, 2018

Two and a half years ago, a team of researchers led by groups at MIT, the University of California at Berkeley, and Boston University announced a milestone: the fabrication of a working microprocessor, built using only existing ...

Atoms may hum a tune from grand cosmic symphony

April 19, 2018

Researchers playing with a cloud of ultracold atoms uncovered behavior that bears a striking resemblance to the universe in microcosm. Their work, which forges new connections between atomic physics and the sudden expansion ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.