A global team of researchers has partnered up with the Māori tribe Ngātiwai to sequence the genome of the tuatara, a rare reptile endemic to New Zealand. Their work, published online on August 5, 2020 in Nature, lays the foundation for understanding the evolution of this ancient species, and can inform conservation efforts to protect it. The open-access article is titled "The Tuatara Genome Reveals Ancient Features of Amniote Evolution." The study included collaborators at the University of Otago (New Zealand) and at European Molecular Biology Laboratory’s European Bioinformatics Institute (EMBL-EBI). With its small, scaly body, pointy tail, and clawed feet, the tuatara seems to tick all the boxes to be a lizard--yet it isn't. This ancient reptile is the sole survivor of its own evolutionary branch on the tree of life, the Sphenodontia. Until now, biologists had not reached consensus on the evolutionary history of tuatara--whether they are more closely related to birds, crocodiles, and turtles, or if they stemmed from an ancestor shared with lizards and snakes. "Our research confirms that tuatara have diverged from the ancestor of lizards and snakes about 250 million years ago," says Matthieu Muffato, PhD, the Analysis Lead from Ensembl Comparative Genomics at EMBL-EBI. "This long period of independent evolution explains why we found the tuatara genome to be so unlike those of other vertebrates." "The tuatara genome is considerably bigger than the human genome, and it has a unique constitution. It contains a lot of repetitive DNA segments that are unique to the species and have no known function," explains Fergal Martin, PhD, Vertebrate Annotation Coordinator at EMBL-EBI. The sequence of the tuatara genome revealed a number of aspects of this reptile's lifestyle.
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