UC part of worldwide project on big bang of bird evolution

Canterbury researchers part of worldwide project on the big bang of bird evolution

December 12, 2014

Two University of Canterbury biological scientists are part of a massive international effort that sequenced the genomes of 45 bird species helping unearth the best revolutionary framework map for birds to date.

Dr Paul Gardner and Dr Tammy Steeves have researched various birds, including two New Zealand natives, the rifleman and the kea, to help shape a new bird family tree.

The international project involving more than 200 scientists around the world looked at how modern birds emerged from a mass extinction event that wiped out the dinosaurs 66 million years ago.

Dr Gardner says for all their biological intricacies, birds are surprisingly light on DNA. This big project found that compared to other reptile genomes, avian genomes contain fewer of the repeated DNA sequences and lost hundreds of genes in their early evolution after birds evolved from other reptiles.

“Our group found that the genomic structure of birds has stayed remarkably constant among species for more than 100 million years. The rate of gene evolution across all bird species is also slower compared to mammals,” Dr Gardner says.

“What this means is that if a gene was on one chromosome in the chicken, it’s on the same chromosome in the kea, the rifleman and everything in between. Our goal was to have a representative species for each of the major branches of modern birds, the rifleman represents one branch, and the kea another.’

Dr Gardner says the Canterbury research team is excited to be making contributions to such a major worldwide scientific effort.

“We were minor players in this major international effort. Nevertheless, our University of Canterbury team added a lot of value as the RNA genes that we studied are a bit fiddly to deal with, which means they are often overlooked in genome sequencing projects.

“One of the beautiful things about bird genomes is that they are incredibly compact; they are a third the size of the human genome. This is exciting for us because broken copies of RNA genes litter most genomes. One class of RNA genes has one million copies scattered throughout the human genome, but birds are refreshingly free of these. It makes the analyses much easier and saves a lot of time on our super-computer.”

As well as uncovering the genetic details of how birds arrived at the spectacular biodiversity of more than 10,000 species worldwide, the Canterbury research work is paving the way for a new era of the conservation of bird biodiversity in New Zealand.

“Ultimately, we want to preserve the genetic diversity of threatened species so they have the ability to adapt to environmental change. How we measure that diversity and how we make decisions about how best to preserve it is changing, from having information for just a few genes to thousands of genes.”

University of Canterbury conservation geneticist Dr Steeves says she is confident the publication of 45 new bird genomes will lead to a surge of conservation genomics research in New Zealand.

“Having so many new bird genomes, especially for threatened species like the kea and at risk species like the rifleman is exciting,” Dr Steeves says.

“Our future work includes tackling the exciting and challenging genomes of charismatic species in collaboration with national and international research groups.

“These include the tuatara, kiwi and the giant squid. We would love to look at bat genomes too, since like birds, they have delightfully compact genomes.”

The research team’s findings are part of two flagship papers authored by more than 200 consortium members, which hail from 80 institutions in 20 countries and was led by Chinese academics, the University of Copenhagen and Duke University. The study was published today in the latest issue of Science.

ENDS

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