Research Findings Advance Our understanding of Gene Expression

Until the research reported in two papers published in today’s prestigious scientific journal – Nature, it had been presumed that in the chemical process of methylation(when a gene is turned on or turned off) a gene was stable and unchangeable.

However, arising from the findings of this research group at the European Molecular Biology Laboratory in Heidelberg in Germany which included Dr. George Reid, EMBL Professor in Heidelberg, it has been shown that this is not the case and that the methylation process is transient, cyclical and dynamic. This insight came from an approach of synchronising all cells in a population such that variations were made visible.

With the sequencing of the human genome the general public has become very aware that the answer to many diseases lies in our DNA. Crucially, only some of the total possibility of genes are expressed in any given tissue. For example, a protein that is active in a nerve cell is not expressed in the liver. The way in which this is controlled is a complex area that has attracted much research. One fundamental controlling factor is whether the DNA is tagged or modified in the region of a particular gene. This modification (methylation) is important not only in gene expression but also in ensuring that there is the right balance in the level of expression of proteins in different cells. For instance women with two chromosomes have one of these silenced by the same methylation tag such that they have one active X. chromosome as have men. The consequences of an excess level of expression is well know, for instance in Downs Syndrome where an extra chromosome is active.

One paper shows that this is a general phenomenon occurring at many different genes and in many different cell types. The second paper arises predominantly from the work of Raphael Metivier, a former Post Doctoral student of Professor Gannon, carried out in Rennes in France, which shows a mechanism for this newly described phenomenon.

Commenting on the papers, Professor Gannon, said, “ It is a great satisfaction to obtain results which were of the highest standards such that they were accepted in the most discerning journals. More significantly however, the new insights paves the way for research on methods to interfere with the methylation process. As this is central to the expression of genes which are important in cancer and development, it should prove to be a very fruitful area of research”.