Of histones and humans
Professor Iva Zovkic started out studying drug addiction in adolescent rodents, but a couple of conferences during her graduate work got her hooked her on epigenetics and their effects on learning, memory and behaviour, and she has been fixated by its potential ever since.
“When I heard the presentations on epigenetics [the study of external or environmental factors that turn genes on and off and affect how cells read genes] I decided then and there that that’s what I wanted to do, firstly because it’s absolutely amazing, and secondly this changed the way we all think about learning and memory,” says Zovkic, an assistant professor in the Department of Psychology. “I love the idea of being able to study how epigenetic changes happen instantly, but also how they can last for a long time.”
In 2008, a scientific talk given by a postdoc working at McGill University demonstrated that variations in maternal care in early life cause long-lasting alterations in certain types of behaviour, due to epigenetics. Zovkic was intrigued and immediately recognized the relevance of this work to her adolescent mice research.
It was a second conference talk given the following year by a post doc from a lab in the Department of Neurobiology at the University of Alabama Birmingham (UAB) that ultimately sealed her fate in terms of research and where she would pursue a postdoctoral appointment.
Zovkic decided to switch paths to focus on epigenetics, and on memory research in particular. She took her newly awarded NSERC Postdoctoral Fellowship and went to UAB in 2011 to be a part of the innovative lab run by Professor David Sweatt.
Today, Zovkic’s work at UTM focuses on gene regulation in the brain and histone variant exchange in memory formation. Histones are proteins inside the cell nucleus that package DNA, and their modifications are involved in turning memory-related genes on and off in response to learning. These epigenetic modifications of histones and DNA can produce stable changes in gene activity without actually changing the sequence of the gene. In the case of Zovkic’s work, she used a virus to reduce levels of a particular histone-variant, H2A.Z, in the brain.
This led to an important discovery: that H2A.Z, which is typically studied in relation to development and cancer, is also involved in regulating cognitive function. This has several related consequences for this field, for example, it could be used to treat memory-related disorders in the future.
Overall, Zovkic sees huge potential for epigenetics and for histone variants in particular, however there is still much to be discovered about their relationship to memory. Additionally, histone variants are found across species so there are profound implications for this research in a variety of disciplines, including neuroscience, aging, disease and mental health.