A team of researchers have stated that they have sequenced the genome of a Great white shark which reveals a few clues about the capacity of these animals when it comes to resisting cancer and healing wounds. The details of the study have been published in the PNAS journal.
Great white sharks are fascinating, not just because of the their formidable size and physical strength, but also due to their longevity. The predator has sat at the top of the marine life food chain for thousands of years. According to a study, Great Whites were even responsible for the megalodon extinction which was the biggest shark ever alive on Earth. But why are Great White sharks so resistant? Researchers from Nova Southeastern University, Cornell University and the Monterey Bay Aquarium have sequenced a genome to try and understand the impressive creature.
Resistance to illnesses
The researchers hoped to re-transcribe the genetic code of the shark so they could establish what genes are at work in the animal. The first thing to transpires from this study is that natural selection seems to have stimulated the genes involved in DNA tolerance and repair. According to the researchers this explains why this predator is resistant to cancer and other illnesses linked to age. Some specimens of this shark can live for up to 400 years! Several sharks in the oceans today could have been alive when the Great Britain’s flag was created during the reign of James I.
Mahmood Shivji, the co-lead author of the study noted that “Not only were there a surprisingly high number of genome stability genes that contained these adaptive changes, but there was also an enrichment of several of these genes, highlighting the importance of this genetic fine-tuning in the white shark.“
It is also important to note that 30% of the Great white shark’s total genome are (LINE) genes which upset the balance of the genome, which is unheard of for vertebrae. This could be the reason why these sharks have developed reparation DNA like they have.
“These LINEs are known to cause genome instability by creating double stranded breaks in DNA,” as explains Michael Stanhope, the co-lead author of the study. He continues by saying that an increase in LINEs in the white shark genome could plausibly “represent a strong selective agent for the evolution of efficient DNA repair mechanisms, and is reflected in the positive selection and enrichment of so many genome stability genes.”
Healing of scars
The white shark’s genome also has an increased number of genes which are involved in blood coagulation which is an essential element in healing wounds. Again this seems to explain the animal’s capacity for pulling through injuries that would normally be fatal for humans.
We therefore have a lot to learn from this predator. The instability of the human’s genome encourages the development of many serious illnesses. However now it is clear that nature has developed alternative strategies so these sharks can be more resistant and live longer. Overtime we could study these strategies developed by evolution so as to take advantage of the positive aspects for ourselves.