It’s “an array of tools, each one finely tuned”:
Our cells are constantly dividing, and as they do, the DNA molecule — our genetic code — sometimes gets broken. DNA has twin strands, and a break in both is considered especially dangerous. This kind of double-strand break can lead to genome rearrangements that are hallmarks of cancer cells, said James Daley, PhD, of the Long School of Medicine at The University of Texas Health Science Center at San Antonio.
Dr. Daley is first author of research, published June 18 in the journal Nature Communications, that sheds light on a double-strand break repair process called homologous recombination. Joined by senior authors Patrick Sung, DPhil, and Sandeep Burma, PhD, and other collaborators, Dr. Daley found that among an array of mechanisms that initiate homologous recombination, each one is quite different. Homologous recombination is initiated by a process called DNA end resection where one of the two strands of DNA at a break is chewed back by resection enzymes.
“What’s exciting about this work is that it answers a long-held mystery among scientists,” Dr. Daley said. “For a decade we have known that resection enzymes are at the forefront of homologous recombination. What we didn’t know is why so many of these enzymes are involved, and why we need three or four different enzymes that seem to accomplish the same task in repairing double-strand breaks.” …
“It’s like an engine mechanic who has a set of tools at his disposal,” Dr. Sung said. “The tool he uses depends on the issue that needs to be repaired. In like fashion, each DNA repair tool in our cells is designed to repair a distinctive type of break in our DNA.”
University of Texas Health Science Center at San Antonio, “When it comes to DNA repair, it’s not one tool fits all” at ScienceDaily
Paper. (open access)
Isn’t it amazing how all this fine-tuning “just happened.” Clearly, there is an order behind nature that did not just happen. If mathematics governs the universe, we should be trying to find out what really happened. It should be possible to find out if these complex structural developments are based on laws, not randomness.