We all started as single cell. From that single cell, through thousands of replications and cell divisions, came all the different cell types that make up our bodies. What makes a skin cell a skin cell and a lung cell a lung cell, despite all cells in our body having the same genetic material inherited from our parents? This largely has to do with the unique combination of genes that are turned on or off in different cell types. Once this cellular identify is established it is essential that, as cells replicate to rejuvenate, they remember exactly which genes are turned on and off. Researchers have long wondered how cells maintain their memory, as when it is not maintained it leads to many diseases, especially cancer.
Dr. Jean-François Couture and his post-doctoral student Elisa Bergamin, along with collaborators, have solved this mystery. In a paper published in Science (Science. 2014 Mar 14;343(6176):1249-53. doi: 10.1126/science.1248357), they report the fundamental discovery that a specific variant of histone H3, which DNA is wrapped around, serves as a “memory stick” for the cell.
So what exactly does this mean? This discovery could be applied to just about any health research, from cancer biology to Alzheimer’s disease. Now that researchers know how cellular identity is established, the search is on to see if we can re-establish memory in cells whose memory sticks have failed.
Watch a video of Dr. Couture explaining his discovery on CBC News.