The entirety of our genetic information is encoded in our DNA. In our cells, it wraps together with proteins to form a flexible fiber about 2 metres long known as chromatin. Despite its length, each cell in our body keeps a copy of our chromatin in its nucleus, which is only about 10 microns across. For scale, if the nucleus was the size of a basketball, its chromatin would be about 90 miles long. How can it all fit in there? To make matters worse, the cell needs chromatin to be easily accessible for reading and copying, so it can’t be all tangled up. It’s not surprising then that scientists have been puzzled as to how this packing problem can be reliably solved in every cell. The solution is to pack the chromatin in a specific way, and research suggests that this may be in the form of a “fractal globule”.
I was ready. I was so ready. I had all my chargers and AV adapters. My presentation was backed up on a USB drive. I had every talk I wanted to go to on my calendar. I had sent emails to professors I wanted to meet and network with. I reached out to friends I only see in March in a different city every year. It was 10 pm on Saturday, February 29. My flight to Denver was leaving at 6 am in the morning. Then the email arrived —
Our bodies are made up of cells that can sense and respond to their dynamic environment. As an example, pancreatic beta cells chemically sense increased blood sugar concentrations and respond by producing insulin. Scientists have found that cells can also mechanically sense their environment; “mechanosensing” determines whether a cell should grow or die. Cancer is characterized by uncontrolled cellular growth, where cells often contain mutations that inhibit the natural mechanisms of cell death. Because mechanosensing is one such mechanism, scientists have hypothesized that cancer cells keep growing because they lack the ability to probe their environments. In this week’s paper, published in Nature Materials, an international research team led by Bo Yang and Michael Sheetz from the National University of Singapore investigated that hypothesis by combining tools from soft matter physics and biology.