Introduction
Epigenetic processes begin before birth and continue throughout one’s life. In old age, people are much more influenced by epigenetic mechanisms inherent in intrauterine development than by a person’s own lifestyle. Epigenetic modifications can be passed on to subsequent generations, affecting various phenotypic manifestations in children and even grandchildren (Feng-Yao & Rui-Xing, 2022). The management of epigenetic processes opens up huge prospects for humanity. With the help of directed gene expression, people can gain physical and mental benefits, infinitely regenerate organs, and significantly prolong life. That is an important incentive for the study of epigenetics.
Basic Molecular Properties of Genes
A gene, as a unit of functioning of hereditary material, has a number of properties. The first of them is specificity – a unique sequence of nucleotides for each structural gene; that is, each gene encodes its own trait. Moreover, the gene is integral: as a functional unit of protein synthesis programming, the gene is indivisible. The gene is discrete since there are subunits in the gene: muton is the subunit responsible for mutation, and recon is responsible for recombination. Another property of the gene is stability since the gene, as a discrete unit of heredity, is characterized by constancy – in the absence of mutation, it is transmitted unchanged over a number of generations. The frequency of spontaneous mutation of one gene is approximately 1·10-5 per generation (Feng-Yao & Rui-Xing, 2022). In addition, the gene is labile and pleiotropic: the stability of genes is not absolute; they can change, and mutate, and one gene is responsible for several traits.
Regulatory Elements: Activators & Repressors
To start transcription, the RNA polymerase must attach to the promoter. The work of the promoter is regulated by special regulatory proteins, which, by binding to certain parts of DNA, either interfere or help RNA polymerase to begin transcription. These proteins are called site-specific DNA-binding proteins. The main function of these proteins is to turn genes on or off. Regulatory proteins that inhibit promoter activity and, consequently, gene transcription are called repressors (from Lat. repressor — limiting, restraining), and proteins that help RNA polymerase begin transcription are activators (Ramos-Lopez et al., 2022). In bacteria, certain regulatory proteins can function both as repressors and as activators.
Explanation of Epigenetics
Epigenetics is a branch of genetics that studies how behavior and environment affect how genes work. Epigenetics, along with genetic changes, can participate in evolution. Unlike genetic changes, epigenetic changes are reversible. In practice, this means that the social environment, daily routine, and nutrition, physical activity change the way the body reproduces cells and affect the work of all organs (Courbage et al., 2022). This information can even be transmitted genetically.
Explanation of Chosen Article
The article I have chosen is devoted to the analysis of recent progress in the epigenetics of obesity. Its authors are scientists Feng-Yao, W. and Rui-Xing, Y. They note that while a very small proportion of cases of obesity are due to monogenic causes, the increase in the prevalence of multifactorial obesity over the past 50 years is probably due to the complex interaction of environmental factors and individual genetic predisposition (Feng-Yao & Rui-Xing, 2022). Changes in the intestinal microbiome, infectious processes, sleep disorders, associative mating of obese individuals, intrauterine effects, the age of the mother at the time of birth, the duration of breastfeeding, side effects of medications, environmental variability, as well as epigenetic changes according to the study, are considered factors contributing to the development of obesity.
In the article, studies of families, twins, and foster children in ethnically diverse populations were conducted. Scientists have identified the heritability of body mass index (BMI) in 80% of cases. In the last decade, a genome-wide association search has become an effective tool for identifying new genes responsible for the development of obesity. It allowed to obtain new information about the genetics of obesity, but the limitation in understanding the genetic contribution is associated with a large proportion of unexplained BMI variability since the identified single-nucleotide polymorphisms explain <3-5% of the observed variability (Feng-Yao & Rui-Xing, 2022).
Scientists have collected a large amount of data that shows that the variability of body weight is due to individual variability. It is associated with the interaction of genes with the environment, i.e. the so-called epigenetic factors. In turn, non-genetic factors such as nutrition, exercise, or other weight loss measures cause dynamic changes in epigenetic signatures that modulate gene activity (Reichetzeder, 2021). One of the ultimate goals of obesity therapy in the future is to determine an individual’s risk profile based on a combination of genetic and non-genetic factors to predict the development of obesity and concomitant diseases and assess the response to treatment.
The role of the combination of genetic and environmental factors was investigated. The main attention was paid to the analysis of associations between polymorphisms and other factors such as age, gender, physical activity, diet, socio-economic and educational status, and ethnicity. Researchers have shown that physical activity reduces the genetic predisposition to obesity with mutations in the FTO gene encoding a protein involved in energy metabolism and affecting metabolic rate, as well as with a combination of 12 polymorphisms associated with obesity (Feng-Yao & Rui-Xing, 2022).
Enhancing Knowledge about Molecular Properties of Genes
The paper I selected enhances knowledge about the molecular properties of genes allowed deeper insight into the molecular mechanisms underlying the gene-environment interaction. For example, it was found that individual polymorphisms of FTO interact with the nature of nutrition. In particular, a high-protein diet had a beneficial effect on weight loss and contributed to the improvement of body composition in carriers of mutant FTO in the rs1558902 allele (Feng-Yao & Rui-Xing, 2022). In addition, subjects with the FTO rs9939609 allele achieved a better metabolic result after weight loss on a low-fat diet.
Conclusion
Prevention and treatment of obesity are fraught with difficulties since the relationship between biological risk factors and obesity is not completely clear. Epigenetic modifications can translate the effects of environmental factors and behavior into individual biological reactions that contribute to the development of obesity and associated diseases. However, how eating habits and preferences and physical activity affect gene expression through epigenetic mechanisms and how this information can be applied in practice remains unclear.
References
Courbage, S., Poitou, C., & Dubern, B. (2022). Role of genetics and epigenetics in obesity of children and adolescent. Neuropsychiatrie de L’enfance et de L’adolescence, 70(4), 195–200. Web.
Feng-Yao, W., & Rui-Xing, Y. (2022). Recent progress in epigenetics of obesity. Diabetology & Metabolic Syndrome, 14(1), 1–30. Web.
Ramos-Lopez, O., Riezu-Boj, J. I., & Milagro, F. I. (2022). Genetic and epigenetic nutritional interactions influencing obesity risk and adiposity outcomes. Current Opinion in Clinical Nutrition and Metabolic Care, 25(4), 235–241. Web.
Reichetzeder, C. (2021). Overweight and obesity in pregnancy: their impact on epigenetics. European Journal of Clinical Nutrition, 75(12), 1710–1722. Web.