Genetic study of sharks finds protein action much like in humans

A genetic study has found some surprising similarities in humans and sharks regarding the way proteins in both function, U.S. researchers say. A study of a great white shark's genetic code -- the basis of a design so effective it has barely changed since before dinosaurs roamed -- founds proteins involved in an array of different functions, including metabolism, that match humans more closely than they do zebrafish, the quintessential fish model, scientists at Cornell University reported Thursday. "We were very surprised to find, that for many categories of proteins, sharks share more similarities with humans than zebrafish," said Michael Stanhope, Cornell professor of evolutionary genomics. "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." He said the similarity in proteins involved in metabolism was striking. "Sharks have many fascinating characteristics," Stanhope said. "Some give live birth to fully formed young, while some lay eggs. 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," he said.