Study illuminates roles of novel epigenetic chemical in the brain

September 17, 2012

Researchers from the Centre for Addiction and Mental Health (CAMH) have identified a new role of a chemical involved in controlling the genes underlying memory and learning.

"The brain is a tissue, and we know that require various genes to be expressed," says CAMH Senior Scientist Dr. Art Petronis, who is a senior author on the new study. "Our research has identified how the chemical 5-hmC may be involved in the epigenetic processes allowing this plasticity." Dr. Petronis is head of the Krembil Family Epigenetics Laboratory in CAMH's Campbell Family Mental Health Research Institute.

5-hmC is an epigenetic modification of DNA, and was discovered in humans and mice in 2009. DNA modifications are to DNA. They flag genes to be turned "on" – signalling the genome to make a protein – or turned "off." As the overwhelming majority of cells in an individual contain the same , this pattern of flags is what allows a neuron to use the same genome as a blood or , but create a completely different and specialized .

The research, published online in Nature Structural & Molecular Biology, sheds light on the role of 5-hmC. Intriguingly, it is more abundant in the brain than in other tissues in the body, for reasons not clear to date.

The CAMH team of scientists examined DNA from a variety of tissues, including the mouse and human brain, and looked at where 5-hmC was found in the genome. They detected that 5-hmC had a unique distribution in the brain: it was highly enriched in genes related to the synapse, the dynamic tips of brain cells. Growth and change in the synapse allow different brain cells to "wire" together, which enables learning and memory.

"This enrichment of 5-hmC in synapse-related genes suggests a role for this epigenetic modification in learning and memory," says Dr. Petronis.

The team further showed that 5-hmC had a special distribution even within the gene. The code for one gene can be edited and "spliced" to create several different proteins. Dr. Petronis found that 5-hmC is located at "splice junctions," the points where the gene is cut before splicing.

"5-hmC may signal the cell's splicing machinery to generate the diverse proteins that, in turn, give rise to the unprecedented complexity of the brain," he says.

The research team is continuing to investigate the role of 5-hmC in more detail, and to determine whether 5-hmC function is different in people with bipolar disorder and schizophrenia compared to people without these diagnoses.

Explore further: Patterns of new DNA letter in brain suggest distinct function

Related Stories

Patterns of new DNA letter in brain suggest distinct function

October 30, 2011
In 2009, the DNA alphabet expanded. Scientists discovered that an extra letter or "sixth nucleotide" was surprisingly abundant in DNA from stem cells and brain cells.

Hopkins team discovers how DNA changes

April 14, 2011
Using human kidney cells and brain tissue from adult mice, Johns Hopkins scientists have uncovered the sequence of steps that makes normally stable DNA undergo the crucial chemical changes implicated in cancers, psychiatric ...

Recommended for you

An architect gene is involved in the assimilation of breast milk

October 17, 2017
A family of "architect" genes called Hox coordinates the formation of organs and limbs during embryonic life. Geneticists from the University of Geneva (UNIGE) and the Swiss Federal Institute of Technology in Lausanne (EPFL), ...

Study identifies genes responsible for diversity of human skin colors

October 12, 2017
Human populations feature a broad palette of skin tones. But until now, few genes have been shown to contribute to normal variation in skin color, and these had primarily been discovered through studies of European populations.

Genes critical for hearing identified

October 12, 2017
Fifty-two previously unidentified genes that are critical for hearing have been found by testing over 3,000 mouse genes. The newly discovered genes will provide insights into the causes of hearing loss in humans, say scientists ...

Team completes atlas of human DNA differences that influence gene expression

October 11, 2017
Researchers funded by the National Institutes of Health (NIH) have completed a detailed atlas documenting the stretches of human DNA that influence gene expression - a key way in which a person's genome gives rise to an observable ...

Genetic advance for male birth control

October 10, 2017
When it comes to birth control, many males turn to two options: condoms or vasectomies. While the two choices are effective, both methods merely focus on blocking the transportation of sperm.

Researchers uncover new congenital heart disease genes

October 9, 2017
Approximately one in every 100 babies is born with congenital heart disease (CHD), and CHD remains the leading cause of mortality from birth defects. Although advancements in surgery and care have improved rates of survival ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

JVK
1 / 5 (1) Sep 18, 2012
The epigenetic effects of nutrient chemicals and pheromones on intracellular signaling and stochastic gene expression could create a pattern responsible for cell memory of what to eat, which controls reproduction and adaptive evolution via ecological, social, neurogenic, and socio-cognitive niche construction. Is there another model for that? I think that looking at the role of epigenetic chemicals in the brain with a one by one approach is not very cost effective.
JVK
1 / 5 (1) Sep 18, 2012
"...5hmC modifications are quite dynamic; some change during maturation, and some change during the aging process," says senior author Peng Jin, associate professor of human genetics at Emory University School of Medicine. "Based on those alterations, our thought, right now, is that it seems like this 5hmC may represent another layer of gene regulation rather than simply the byproduct of demethylation."

http://www.biotec...471.html

The epigenetic effects of nutrient chemicals and pheromones on gonadotropin releasing hormone, maturation of the brain, and synaptic plasticity linked changes during the aging process also links the sensory environment to 5-hmC and chemical control of genes underlying memory and learning.

Kohl, J.V. (2012) Human pheromones and food odors: epigenetic influences... Socioaffective Neuroscience & Psychology, 2: 17338. http://dx.doi.org...i0.17338

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.