- Scientists from Wisconsin University have attempted to study the genetic basis of radiation resistance by subjecting Escherichia coli to increasing levels of Ionizing radiations (IR) to develop a highly resistant variety.
- The team started with a library of radiation resistant E.coli cells, each cell had a different gene inactivated by the method of Transposon Directed Insertion Sequencing (TraDIS).
- If a particular gene is essential for recovery from IR, all cells in which that gene was inactivated would die when subjected to IR.
- This enabled them to identify 46 genes that are generally not necessary for the organism’s survival, but are vital when exposed to high levels of IR.
- Out of these, 20 had DNA repair functions and the rest were concerned with protection from oxidative damages, cell division control, cell wall maintenance and others.
- The functions of 8 of the genes were unknown. One of these yejH, was similar to a human gene XPB.
- This may help understand key pathways in humans that help protect us from cancer. IR is lethal in to living cells in high doses since it can cause damage to the proteins, chemically alter the DNA, lead to breakage of DNA strands and cause them to be cancerous.
- The ability of some cells to resist DNA breakage on exposure to IR has been attributed to DNA repair mechanisms and their ability to protect their proteins. However, these studies have revealed that there may be more mechanisms involved.
- Read at:http://www.thehindu.com/todays-paper/tp-features/tp-sci-tech-and-agri/what-makes-cells-resistant-to-radiation/article6243480.ece