Even discriminating sushi connoisseurs would envy the tuna George Amato has sampled. The purpose of the tasty experiment: Use DNA barcoding to find out if threatened species of tuna are sold in the United States market.
Barcoding relies on a short fragment of mitochondrial DNA found in virtually all living things. The 650 base-pair region, part of the cytochrome oxidase I (COI) gene, accumulated mutations at a high rate during evolution, and can now be used to distinguish between many related species of animals or insects. “It’s one of the best species identifiers,” says Amato, director of the American Museum of Natural History’s Sackler Institute for Comparative Genomics. “Although tuna barcodes are a little more tricky.”
That’s because species of tuna are closely related, so their barcodes show little variation. While Amato has used barcodes to distinguish threatened gorillas, sea turtles, and crocodiles from their common relatives, researchers have debated ...
