Important secrets of moa DNA uncovered

Jamie Morton

The DNA secrets of what was our most common species of moa have been revealed in a new Harvard University study that one scientist says could be “game-changing”.

The team used a new form of DNA sequencing, called high-throughput sequencing, to unravel the little bush moa’s nuclear genome, or the makeup of a species’ nuclear DNA.

Analysing mitochondrial DNA, which is passed down maternally, has enabled scientists to learn about species’ evolution. But downloading their nuclear DNA, the genetic building-blocks responsible for determining or “coding” much more, lets researchers look even deeper.

In a just-published study, experts from Harvard and Canada’s Royal Ontario Museum used ancient DNA (aDNA) extracted from a single toe bone of a specimen of little bush moa.

They and all other moa were hunted to extinction soon after man arrived in the 13th century.

First retrieved by Kiwi paleozoologist Professor Trevor “Mr Moa” Worthy, the specimens had been held at the Royal Ontario Museum.

Along with a near-complete mitochondrial genome, Dr Alison Cloutier and colleagues recovered nearly 900 megabases of the moa nuclear genome by mapping reads to a high-quality reference genome for the emu. The team also isolated 40 repeating tracts of DNA, called polymorphic microsatellites, that could help scientists carry out populationlevel studies of moa.

“This first nuclear genome assembly begins a new chapter in the already extensive history of moa aDNA research,” the authors concluded.

Having the new moa nuclear genome would help studies of regulatory changes linked with flightless creatures, including kiwi.

Dr Nic Rawlence, Otago University lecturer in ancient DNA, said the new insights would prove important.

“This will be a game-changing moment in our understanding of the evolution of New Zealand’s unique fauna,” he said.

“The sequencing of the first draft moa genome . . . will allow scientists to finally bring the power of the genomic revolution that has swept through science to answering some of the big questions regarding moa evolution and how they responded to New Zealand’s dynamic geological and climatic history.

“Already, it looks the cause of moas’ complete lack of wings may not be a simple case of gene loss . . .”