AP Biology class blog for discussing current research in Biology

Tag: epigenome

Editing the Brain Using Epigenetic Tools

Epigenetics is a huge part of our life and influences us in ways we may not be aware of. Did you know that it is impossible to create and save new memories without epigenetic tags? The brain is heavily reliant on Epigenetics to do its functions, and this makes it a huge topic of research to figure out the ways in which the epigenetics of the brain could affect certain diseases or memory. Recently special epigenetic molecular tools have been created that can erase specific epigenetic markers throughout the genome. The possible effects these tools could have on the curing of diseases of the brain or psychological ailments are tremendous.

These “epigenetic editing” procedure use either CRISPR (clustered, regularly interspaced, short, palindromic repeats) or TALE (Transcription activator-like effector) systems of modification. These systems can carry an Epigenome modifying enzyme and deliver it a specific site they are programmed to go to. This allows researchers to target very specific epigenetic changes and either shut them down or turn them on and possibly determine their correlation with certain ailments of the brain. “We’re going from simply being able to observe changes to being able to manipulate and recapitulate those changes in a controlled way,” Day said. This quote from Day, one of the researchers of this project, shows that we advance from only being able to observe epigenetic influences on the brain, to being able to manipulate and control them to potential aid us in combating diseases.

Researchers can catalog all of the epigenetic changes involved in forming and preserving a new memory. If we are able to track these epigenetic changes, then could we implant memories in to a person’s mind, by copying similar epigenetic changes? These researchers where also able to trigger not only the place where epigenetic change happens, but also the exact time using optogenetics. This form of using light to control neurons allows researchers to use the TALE system and a light switch apply epigenetic change to very specific brain regions or cell types.

One of the final goals of this research is to eventually be able to use epigenetic as a form of therapy to benefit PTSD, depression, schizophrenia, and cognitive function using the ability to alter epigenetic marks. This can also be used in a similar way to silence mutated genes that are damaging the cells or the body as whole. This form of using TALE and CRISPR to alter epigenetic tags creates a lot of hope for PTSD, depression, schizophrenia, Alzheimer’s, Parkinson’s, Huntington’s and other similar disease treatment options.

Long Term Effects of Bad Diet Linked to Epigenome

Epigenetics has become an increasingly popular topic of scientific study. It is universally understood that DNA carries genes, however the expression of those genes are at the whim of the epigenome. The long-term control of the epigenome over the expression of certain genes is not yet fully understood. Scientist Erik van Kampen of the Leiden Academic Centre for Drug Research at Leiden University in The Netherlands studies epigenetics. He was interested in the mystery of how the epigenome is influenced by diet. He explored the idea of how the effects of a poor diet continue to persist even after a better diet is adopted.

In his study, he used mice that naturally had a high susceptibility to getting high blood cholesterol and atherosclerosis. He fed these mice either a high fat, high-cholesterol diet or a normal diet. After time had passed, bone marrow was isolated from both the unhealthy and healthy diet mice. This bone marrow was transplanted into mice that had their bone marrow destroyed. The new mice with borrowed bone marrow were given a healthy, normal diet for several months. After this time had passed, the mice were measured for development of atherosclerosis in the heart. In addition to this, the mice were measured for the number and status of immune cells throughout the body and epigenetic markings on the DNA in the bone marrow.

The results of this study were staggering. Mr. Kampen found that DNA methylation (which inactivates the expression of genes) in the bone marrow was different in both types of mice. The transplants received from the unhealthy diet mice were seen as having a decreased immune system and increased atherosclerosis in comparison to the ones who had healthy donors. This study proves at least somewhat of a correlation between diet and long-term effects on the body and the expression of genes.

The original article can be found at this address:

Can Stress Affect Pregnancies in Later Generations?

We all know stress isn’t always a good thing, but it could be important to especially avoid it at certain points in one’s life. Recently researchers from the University of Lethbridge in Canada investigated the effects of stress on pregnancies and how it can influence pre-term births. It is already known that pre-term births them selves lead to health issues later in life, but there were some new discoveries involving epigenetics.




These researchers studied the length pregnancies of rats, due to the generally small amounts of variation between them, and found something intriguing. They carried out the experiment by first splitting the first generation of rats into “stressed” and “not stressed” groups. What they found was that the daughters of stressed rats had a shorter pregnancy than the daughters of not stressed rats.

This trend continued into the granddaughters of the rats. They also displayed high levels of glucose than the control group, and they weighed less. The stress also compounded, or increased, through generations.

This can all translate into human pregnancies. The researchers believe that the epigenetic changes in the rats is due to microRNA (miRNA) – non-coding RNA molecules that play a role in regulating gene expression. They bind to complementary mRNAs and prevent them from being translated. This is different than what is usual belief with epigenetics which is that epigenomes are affected by DNA methylation of the nucleotide base pairs. Metz, a scientist working on this research states that microRNAs “are important biomarkers of human disease, can be generated by experiences and inherited across generations. We have now shown that maternal stress can generate miRNA modifications with effects across several generations.”

It is very similar to the information found with the generational epigenetic effects of famine in the “Ghost in Our Genes” video that we watched in class.

This research can help determine pre-term births and the causalities that can come along with them. While the research is still not the whole picture, it is another step towards understanding our genetics.


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