Mark Ragan and Tim Harlow

New research into the genetic make-up of bacteria has strengthened scientists? suspicions that horizontal gene transfer occurs in the natural world more often than previously accepted.

Up until the early-to mid-1990s, scientists had little reason to doubt the traditional theory of gene transfer first outlined by Darwin and Mendel - that genes were inherited in a 'vertical' manner, passed along from parents to their offspring.

Professor Mark Ragan from UQ?s Institute for Molecular Bioscience (IMB) said that if this was strictly true, statistical analysis of each and every gene family should reveal this 'common heritage' or the 'universal tree of life'.

"By the late 1990s, advances in genomic science had generated enough data to test this prediction and it turned out that, while there was general agreement with this theory, there were many disagreements in detail," Professor Ragan said.

"The identification of horizontally transferred genes required several advanced statistical methods to analyse DNA sequences.

"My work at the IMB applied four statistical methods of analysis to the genome of the common gut bacterium Escherichia coli and the results suggested that some genes had been transferred horizontally into the E. coli genome very recently, whereas others appeared hundreds of millions of years ago."

Professor Ragan said this interpretation had now received confirmation from leaders in the field pursuing similar research interests in the United States.

"The evidence now suggests bacterial genomes are far more dynamic than we realised, and that horizontal gene transfer has been occurring for a very long time," he said.

"A better understanding of horizontal gene transfer will help inform public debate on bioremediation, genetic engineering, protection of biodiversity, and other issues of societal importance."

Professor Ragan was the only Australian scientist invited to attend the prestigious meeting of the Canadian Institute for Advanced Research recently, where scientific issues arising from horizontal gene transfer were intensively debated.

Rigorous analysis of gene transmission in bacteria, along with many other advanced applications in biotechnology, chemistry, Earth sciences, engineering and economics will be supported by new supercomputing facilities at The University of Queensland, and at the Australian Partnership for Advanced Computing (APAC) national facility located at the Australian National University

Based at UQ, the IMB is one of Australasia's leading research institutions and a major centre for molecular bioscientific research. It links leading genomic discovery and advanced bioinformatic facilities with state-of-the-art research contributing to world knowledge in the areas of human health and animal biology.

Research team

Professor Mark Ragan (IMB) www.uq.edu.au/uqresearchers/researcher/raganma.html
Tim Harlow (IMB)
Dr Robert Charlebois (NGI Inc., Ottawa)
Associate Professor Jeffrey Lawrence (University of Pittsburgh)
Professor Mark Borodovsky
(Georgia Institute of Technology)

Funding

IMB core funding and Canadian Institute for Advanced Research. 2000-2008 Infrastructural support supplied by the Australian Research Council Special Research Centre for Functional and Applied Genomics, ($1 million per year subject to triennial reviews)

Email
m.ragan@imb.uq.edu.au

Web links
www.imb.uq.edu.au/Ragan.html
www.imb.uq.edu.au/bioinformatics

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