Researchers find genetic switch

Australian and United States researchers have, for the first time, mapped the genetic switches that determine the epigenetic inheritance code for plants, paving the way for studies on humans that could unlock the secrets of cancer and other diseases. 

The study, involving two researchers from The University of Western Australia and researchers from the Salk Institute for Biological Sciences in San Diego, California, has been able to show for the first time the exact location of over 2 million methylation points in the plant genome.

"Imagine a sound-studio mixing desk, full of switches, sliders, knobs and dials, all set to specific levels to control the sound being produced by musical instruments," said University of Western Australia researcher Prof Harvey Millar. "Now apply this picture to the thousands of genes that you inherited from your parents and imagine that each gene is an instrument. Many of us are aware of the inheritance of our genes, but did you know that you also inherited the mixing desk? The precise settings of some of the controls on your genetic mixing desk can be traced back through your family for generations."

The settings of these switches are called ‘methylation points' and the science focused on unlocking their secret code is called Epigenetics. Until recently scientists did not have a clear picture of how many methylation points a biological system had, or the tools to find them all.

The research project has also gone on to show that removing methylation can change the expression of thousands of genes without ever changing the sequence of the DNA.

These ground-breaking new results, published on 18 April in the leading international journal Cell, provide new avenues for research in plants and humans.

Sequencing the epigenetic code (the epigenome) of a plant provides new directions for research in plant breeding, food production and tolerance to environmental change. When the same can be achieved in humans it will lead to improvements in disease diagnosis and understanding and controlling cancer. Plant scientists are paving the way for such analysis in humans by establishing the technologies needed for epigenome sequencing.

UWA researcher Julian Tonti Filippini designed and built the revolutionary software called "AnnoJ", as part of his PhD, to analyse the methylation code. The software tool has allowed this study to map the epigenetic footprints across the plant genome, giving a clear, complete view of the epigenome for the first time.

"The development of these types of tools is imperative for gaining a better understanding of how methylation operates within a biological system such as plants or humans," said Prof Millar, a co-author of the study and Mr Tonti Filippini's supervisor.

"It's a complex interplay between inherited genes and these methylation point switches. Julian's programming and data analysis skills have been essential for the project and AnnoJ is set to have an impressive start to life by showcasing the epigenome. There is already substantial interest from other researchers internationally to begin analysing their data by this approach."  

Editor's Note: Original news release can be found here.