Sharks Humans Proteins In Common
December 6, 2013

Great Whites And Humans Share Remarkably Similar Proteins, Says Study

redOrbit Staff & Wire Reports - Your Universe Online

Many shark proteins, involved in a number of different functions, match those of humans more closely than they do those of zebrafish. Cornell University researchers reported  this resemblance on Thursday, after an extensive investigation into the genetic code of endangered great white sharks.

Despite a longstanding fascination with great whites, whose body design has been so effective that it has barely changed since the time of the dinosaurs, the world’s oldest ocean predators have long been a genetic mystery.

Michael Stanhope, professor of evolutionary genomics at Cornell’s College of Veterinary Medicine and lead author of the study, said the current analysis lays the foundation for genomic exploration of sharks, and vastly expands genetic tools for their conservation.

The study was launched after Stanhope and Nova Southeastern professor Mahmood Shivji received a grant from the Save Our Seas Shark Research Center, along with a rare gift of a great white shark heart that had been autopsied from an illegally fished shark, confiscated by authorities and donated to their project.

“We were very surprised to find that for many categories of proteins, sharks share more similarities with humans than zebrafish,” Stanhope said. The researchers were particularly interested in findings that revealed the sharks had a closer match to humans for proteins involved in metabolism.

“Although sharks and bony fishes are not closely related, they are nonetheless both fish … while mammals have very different anatomies and physiologies. Nevertheless, our findings open the possibility that some aspects of white shark metabolism, as well as other aspects of its overall biochemistry, might be more similar to that of a mammal than to that of a bony fish.”

“Sharks have many fascinating characteristics,” he added. “Some give live birth to fully formed young, while some lay eggs. In some species, the embryos eat the remaining eggs or even other embryos while still developing in the uterus. Some can dive very deep, others cannot. Some stay local; others migrate across the entire ocean basins. White sharks dive deep, migrate very long distances and give live birth. We will use what we’ve learned in this species in a broader comparative study of genes involved in these diverse behaviors.”

Because sharks are apex predators, their declining number threatens the stability of marine ecosystems that millions of people rely on for food.

Stanhope said the current study has increased by a thousand fold the number of genetic markers scientists can now use to study the population biology of great white and related sharks. This information can further expand knowledge of these fascinating animals, many of which are in urgent need of conservation, he said.

The study is published in the November issue of BMC Genomics.