Whole Tuatara Genome Sequence Completed
The tuatara are endemic to New Zealand and are part of the order Rhynchocephalia.
Tuatara (Sphenodon punctatus), are lizard-like reptiles endemic to New Zealand and are the only living member of the reptilian order Rhynchocephalia (Sphenodontia). It was announced that the species has had its whole genome sequence completed by researchers with the University of Otago, Dunedin, New Zealand and the Ngatiwai, the Maori people who have guardianship over the tuatara populations that were used in the study.
This collaboration enabled genomicists Neil J. Gemmell and Kim Rutherford to create one of the largest vertebrate genomes published, at more than 5 gigabases. The Maori people were involved with all decision-making processes regarding the study and are listed as authors of the paper as well.
The researchers complemented the genome by generating gene expression profiles for tuatara blood and embryos and conducted preliminary analysis of active and inactive sections of the genome, according to an article on Nature.com.
“Phylogenetic analyses indicate that the tuatara lineage diverged from that of snakes and lizards around 250 million years ago,” the researchers wrote in their paper. “This lineage also shows moderate rates of molecular evolution, with instances of punctuated evolution. Our genome sequence analysis identifies expansions of proteins, non-protein-coding RNA families and repeat elements, the latter of which show an amalgam of reptilian and mammalian features.”
The complete paper, “The tuatara genome reveals ancient features of amniote evolution, can be read on the Nature.com website.
The tuatara are endemic to New Zealand and while they resemble lizards, they are part of the order Rhynchocephalia and the two species in New Zealand are the only surviving members in their 250 million year old family. The tuatara shared a common ancestor with reptiles about 250 million years ago. The species is an important link between the extinct stem reptiles of which dinosaurs, modern reptiles, mammals, and birds evolved. Tuatara can live more than 100 years and reach sexual maturity at 10-20 years.