site.btaProf. Vassileva on Epigenetics, Their Significance for Humans and Crops

Although genetic research has mainly focused on the role of DNA in determining the characteristics of an organism, in recent years it has become increasingly clear that genes are not static entities but can be influenced by internal and external factors such as climate, diet, stress, social interactions, etc. Epigenetic research in Bulgaria is linked to biomedicine, with few scientists working on plant epigenetics, despite its importance in the context of climate change, Valya Vassileva, Director of the Institute of Plant Physiology and Genetics at the Bulgarian Academy of Sciences told BTA in an interview.

Between May 30 and June 1, the third EPI-CATCH International Conference, a forum of world scientists interested in this field of science, takes place in Sofia.

Understanding epigenetic mechanisms in plants can help researchers develop strategies to improve traits of important economic crops such as increased resistance to stress and disease, better nutritional value and yield, which will ensure food security, Vassileva said.

In terms of humans, the study of epigenetic regulation is known to provide potential opportunities to partially overcome some inherited diseases, lifestyle choices can reduce the risk of their development and mitigate their impact on organisms, the scientist said. 

Epigenetic research can contribute to the development of a personalized medicine approach. By analysing an individual's epigenetic profile, it is possible to identify specific epigenetic modifications associated with inherited diseases and tailor treatment strategies accordingly. This personalized approach could lead to more effective and precise treatments for individuals at risk, Vassileva added.

She said that epigenetic changes can be inherited in offspring. As long as the DNA sequence itself remains unchanged, epigenetic modifications to DNA and associated proteins can be passed from one generation to the next. This phenomenon is known as transgenerational epigenetic inheritance. This type of inheritance suggests that the effects of environmental factors experienced by an individual can be passed on to its offspring through epigenetic modifications. For example, it has been found that certain influences, such as diet, stress, and exposure to toxins, can lead to epigenetic changes in germ cells or early embryos. In a number of serious diseases such as Alzheimer's, tumors, diabetes, multiple sclerosis, and depression, certain genes are in a state of activity opposite to normal. These changes can be passed on to subsequent generations, affecting gene activity patterns and therefore the phenotype and health of offspring. It is important to note, however, that not all epigenetic changes are inherited. Some are dynamic and may disappear or be altered during the early development of individuals, while others may be passed on to subsequent generations. The extent and stability of epigenetic inheritance depends on the type of epigenetic trait, the genomic regions affected and the environmental conditions.

Vassileva noted that despite the optimism surrounding the potential of epigenetic regulation to overcome inherited diseases, it is important to note that much research is still needed to fully understand the complexities and limitations of epigenetic interventions. A multidisciplinary approach involving genetics, epigenetics, environmental sciences, and clinical research is required to reach a practical application of these findings. In addition, ethical principles need to be considered and potential risks and benefits carefully assessed. 

She shared that her field of work focuses on plant epigenetics. The studies in her laboratory entail DNA methylation, an epigenetic modification in which a methyl group is added to the DNA molecule by enzymes called methyltransferases. Methylation alters the expression level of the gene, acting as a barrier that prevents the molecular machinery from accessing the DNA. Simply put, when methylation is increased, the gene is inactive or has reduced activity, but methylation also leads to activation of some genes. Mutations in the methylation systems of animal organisms are lethal, making them difficult to study. Alternative experimental systems are therefore being sought for study. Interestingly, methylation mechanisms in mammals are more similar to those in plants compared to other animal species. Unlike mammals, however, plants are tolerant of changes or lack of methylation and can produce offspring, making them a great experimental system for studying methylation mechanisms. We use the model plant Arabidopsis thaliana to study and compare methylation mechanisms in mammals and plants. We are investigating the characteristics of enzymes that are critical for maintenance DNA methylation in these organisms.

In Bulgaria, interest in epigenetic research is growing, with scientists and research groups actively engaged in this field, Vassileva said. Bulgarian researchers are involved in studying the role of epigenetic modifications in various diseases and their potential therapeutic use. Although Bulgaria has not received worldwide recognition in epigenetic research to the same extent as some other countries, there are talented scientists working to expand the country's presence in this field. Most of the epigenetic research is related to biomedicine, with very few scientists working on plant epigenetics. Due to the extreme importance of these issues in the light of climate change, the scientific community in Bulgaria needs to keep abreast of new developments in plant epigenetics and researchers need to be actively involved in international conferences, training workshops and collaborations.