Komodo dragon genome is legacy of Zoo Atlanta animals

New study provides groundbreaking insights into the evolution of lizards.

Two Komodo dragons from Zoo Atlanta will leave an indelible legacy in the global scientific community: the sequencing of the Komodo dragon genome. Published in the journal Nature Ecology & Evolution on July 29, a new study from researchers at the Gladstone Institutes, in a close collaboration with scientists at UC San Francisco and Zoo Atlanta, provides the first high-resolution sequence of the Komodo dragon, as well as insight into how the species evolved. The Komodo dragon is only the second lizard species to be fully sequenced and the first monitor lizard to be sequenced.

Scientists determined the entire sequence of DNA coded in the genome of Zoo Atlanta Komodo dragons Slasher (1992-2013) and Rinca, now 8 years old. The biological samples used in the study were subsets of blood samples collected as part of the animals’ routine veterinary exams. The project was led by Benoit Bruneau, PhD, Senior Investigator at Gladstone and senior author of the paper.

Weighing up to 200 pounds, Komodo dragons are Earth’s largest lizards. As cold-blooded reptiles, monitor lizards such as the Komodo dragon have a remarkable ability to speed their metabolism, resulting in unusually prolonged stamina in physical activities such as hunting, swimming, and wrestling for mates. Until now, however, little has been known as to how these special mechanisms for energy production evolved.

As the only sequenced monitor lizard genome, the Komodo dragon genome is an important resource for understanding the biology of these lizards and of reptiles and all other vertebrate animals worldwide. In determining the genetic bases for the lizards’ exceptional stamina, scientists also discovered that Komodo dragons have evolved special mechanisms of energy production in their cells, as well as unique features of their circulatory systems, including special abilities to control blood pressure and blood clotting. These latter two findings have implications for future applications in human medicine.

Scientists additionally discovered multiple copies of genes related to the sense of smell. These are presumably responsible for Komodo dragons’ extraordinary sensory abilities; they are known to be able to scent prey from up to 7.5 miles away.

“It was a distinct honor to have sequenced these beloved members of Zoo Atlanta. What their genomes revealed will be tremendously important for conservation work and of course for more deeply understanding these fascinating creatures,” Bruneau said.

Herpetologist and evolutionary vertebrate biologist Joseph R. Mendelson, PhD, Director of Research at Zoo Atlanta, oversaw the interpretation of the data to ensure it was relevant and in context with the natural history of monitor lizards and other vertebrates used in the comparisons.

“We often talk about the importance of preserving biodiversity for biodiversity’s sake, and to maintain the health and functioning of interconnected ecosystems that support all life on Earth. This project brings to the forefront another, lesser-known aspect of the need to preserve biodiversity,” said Mendelson. “We never know what discoveries may be waiting in the future – discoveries that can benefit both humans and non-humans. While they are yet unknown, these opportunities are only possible if we respect and preserve all life.”

The project that resulted in the study was begun nine years ago. The majority of the genetic material used to map the genome were the contributions of Slasher, who already had an important legacy as one of the Zoo’s most beloved animal figures. When Slasher died in 2013 at the age of 20, before the project could be completed, the much-younger Rinca was able to contribute the remaining genetic material.

Read the full paper here.