Sharks are stronger than many realize, Gizmodo is reporting. While everyone knows of their physical strength and the size of their massive teeth, not many people are aware that sharks have strong DNA -- strong enough to ward off life-threatening illnesses like cancer. The largest female great white shark documented, for example, is a whopping 15-feet-long and weighs up to 5,000 pounds. What we don't see, however, is the fact that a great white shark's genome is about 50 percent larger than that of a human.
A new study published in the Proceedings of the National Academy of Sciences analyzed the genes of a shark and compared it to other animals, such as the human. The study was authored by researchers from the Monterey Bay Aquarium, the Cornell University College of Veterinary Medicine, and the Nova Southeastern University (NSU) Save Our Seas Foundation Shark Research Center among others. These researchers were able to identify why sharks seem to be immune to various cancers and other age-related illnesses.
It's interesting to note that the larger a mammal is and the longer it's life-span is (sharks average about 70 years,) the more likely they are to develop harmful mutations over time that can cause cancer and age-related diseases. Not sharks, however. They seem to have a way to dodge this by preventing cells from growing out of control, a trait known as "genetic stability."Another strike against the shark is the fact that it has a certain type of DNA called a transposon, which can jump around the genome. This rearranging of DNA could result in cancer-causing mutations -- but the sharks are able to avoid that as well despite having an unusually high number of transposons. In fact, the transposons may have shuffled in just the right way for sharks to develop a way to prevent diseases. Scientists hope that by continuing to study shark DNA, they will be able to identify how the sharks do it and -- ideally -- discover a way to apply the trait to humans.
"Genome instability is a very important issue in many serious human diseases; now we find that nature has developed clever strategies to maintain the stability of genomes in these large-bodied, long-lived sharks," Mahmood Shivji, director of the NSU Save Our Seas Foundation Shark Research Center, said in a statement.
"There's still tons to be learned from these evolutionary marvels, including information that will potentially be useful to fight cancer and age-related diseases, and improve wound healing treatments in humans, as we uncover how these animals do it."