WIKIMEDIA, HOWARD VINDIPulling on cells can stretch their chromatin, making genes more available to be expressed, researchers reported in Nature Materials this week (August 22).
“[Cells] cannot see or hear, but they can ‘feel’ mechanical forces,” said study coauthor Ning Wang of the University of Illinois at Urbana-Champaign in a statement, adding: “Mechanical signaling is as important as chemical signaling.”
In the cell, DNA resides in the nucleus in a condensed, protein-associated form, called chromatin. Wang and his international colleagues devised a method to visualize the effects of mechanical stimulation on chromatin and, consequently, gene expression.
The scientists inserted into hamster cells a stretch of DNA with evenly spaced LacI repressor-recognition sequences. By also inserting a fluorescently labelled LacI repressor, the team could visualize a few green spots in the chromatin of a live cell. To stretch the cell, the researchers bound magnetic beads to a surface protein. They could ...
