Get ready to start hearing 鈥渆pigenomics鈥� as often as you hear about genomics.
If the genome is like a list of genetic ingredients, then the rules for how those genes are used and when they are switched on and off is the business of epigenetics. The first full piece of this 鈥渃ookbook鈥� has now been sequenced 鈥� a plant鈥檚 epigenome.
Life often modifies its genetic material without changing the letters of the genetic code. One of the main ways this is done is through the addition of a chemical unit called a methyl group to a gene.
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This methylation effectively gums up a gene鈥檚 copying machinery. It is thought to be an important factor in directing stem cells to develop into different tissues, and problems with methylation are implicated in a number of diseases including cancer and Huntington鈥檚.
of the Salk Institute in La Jolla, California and colleagues have used a new method to sequence the complete 鈥渕ethylome鈥� of the cress Arabidopsis for every letter of its genetic code, giving a far more detailed recipe than prior efforts.
Epic genetics
The work is also an improvement on a technique demonstrated in March by of the University of California, Los Angeles. By removing some of the steps that the method requires, Ecker鈥檚 team have greatly speeded up the process of sequencing epigenetic data.
The method produces lots of data 鈥� the Arabidopsis genome comprises some 120 million DNA bases 鈥� so the team has developed to 鈥渂rowse鈥� the genome and find where methylation is controlling gene expression. The program will be able to track more epigenetic data as it is produced, forming a global resource for collecting and analysing it.
鈥淐apturing this kind of sequence-level information for entire genomes of individual plants or humans is now possible and will soon become routine,鈥� Ecker says. 鈥淚n fact, we have already begun using these methods for sequencing of the human methylome.鈥�
Ecker says that the team will look into how methylation affects the development of human stem cells as they change into other types of cells.
, a molecular biologist at the University of Oregon, calls the work a tour de force. He says that the steep drop in the costs and of sequencing in recent years means that the floodgates are open for epigenomics.
鈥淚t鈥檚 amazing what can be done in a small amount of time with this new technique,鈥� he says.
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