Singapore, May 8, 2008: In decoding the genome of the platypus, a team of researchers from the United States, Australia, England, Germany, Israel, Japan, Spain and New Zealand has revealed important information that will enhance the understanding of other mammals and may lead to the development of new approaches to combat disease in livestock and humans and enhance livestock productivity.

 

The New Zealand researchers have been collaborating with the international consortium of scientists, led by the Washington University School of Medicine in St Louis.  Its findings are this week’s cover story of science journal ‘Nature’. The paper published in Nature analyzes the genome sequence of a female platypus named Glennie from New South Wales, Australia. The project was largely funded by the National Human Genome Research Institute, part of the US Government’s medical research agency, the National Institutes of Health.

 

Prof Neil Gemmell, who was recently appointed to the AgResearch Chair in Reproduction and Genomics at the University of Otago, led the New Zealand based researchers working on the project whilst at the University of Canterbury. As holder of the AgResearch Chair, Prof Gemmell is the first Director of the recently established Centre for Reproduction and Genomics, which brings together the expertise of AgResearch and University scientists.

 

“The platypus is an important animal to study because it is only one of three living monotreme mammals that likely best represent what ancient mammalian ancestors were like when they evolved over 166 million years ago. Understanding the genetic make-up of the platypus tells us what genetic features are common to all mammals, and what features are unique to other mammals including livestock and humans; information that may tell us much about how mammals evolved,” said Prof Gemmell.

 

He further said, “You could say that some of the central genetic building blocks on which all mammals are constructed are contained within the genome of this remarkable animal, and become apparent to us when we compare the platypus to the other mammalian genomes (human, mouse, dog, possum) already sequenced. It is representative of an ancient mammalian group that shares some of the features common to reptiles and birds such as egg laying but exhibits behaviours and traits, like producing milk and suckling its young; traits that define the mammals.

 

Prof Gemmell and his team used supercomputer resources at the University of Canterbury to analyse the genomic distribution and abundance of small repetitive DNA sequences (microsatellites) in the platypus genome that are predominantly viewed as having few, if any, functions. However, Prof Gemmell’s team demonstrated that a substantial proportion of these repetitive sequences were conserved in other species, with some conserved in humans, mice, dogs, possums and chickens.

 

“Scientists now believe that the reason this genetic material is passed down is because it is important in some way. It has been conserved across vast evolutionary time frames and is likely present in every single mammal that exists today.”

 

He says the challenge for scientists now is to find out why this material has been passed down through countless generations and establish what functions it is responsible for.

The international project team compared the platypus genome with genomes of the human, mouse, dog, possum and chicken and found that the platypus shares 82 percent of its genes with them.

 

Prof Gemmell says that while it may seem an obscure animal to study, its unique make-up could lead to significant advancements in scientific knowledge. For example, the male platypus produces venom, which it delivers from spurs on its legs. The venom is a cocktail of proteins that originally had very different functions and incredibly the same proteins are found in snake venom even though platypus and snake venom evolved independently. Understanding more about platypus venom could lead to exciting new pharmaceutical developments.