Genomics of suicide (including epigenetics)

https://www.nature.com/articles/s41380-018-0282-3#Sec1
https://www.sciencedirect.com/science/article/pii/S2352396419300775

Let us begin with the transition.

TABLE 2.1 Some Most Evident Differences Associated With Modernization
 Traditional societies
• Big and stable families
• Adherence to traditions and strict rules, morals, religiosity
• Stability, slow pace of social changes
• High family and community cohesion
• Low anxiety and depression

Modernistic societies
• Unstable and incomplete families
• Competitiveness, priority of personal success, liberalism
• Mobility, high speed of social changes
• Individualism, materialism
• High anxiety and depression
• Technologies and information pressure


Epigenetics
As can be seen from the table, there is an evolution of definitions from rather generalized “processes by which genotype gives rise to phenotype” to more focused “phenotypic variations that do not stem from variations in DNA base sequences and are transmitted to subsequent generations of cells or organisms.” Half of definitions are negative, that is, they stress that epigenetics is based on molecular events that are not touching DNA base sequences. It is, therefore, necessary to give a brief description of these events on the biochemical level and to outline mechanisms of epigenetic inheritance, that is, how these molecular events can pass through mitosis and meiosis. Most sophisticated molecular mechanisms that surround these events are far beyond the scope of this book; actually, they can be deeply understood only by those who are specializing in modern molecular genetics. On the contrary, any medical or psychological specialist, who has been educated in the classical tradition, may need an objective picture of these events (as the author has felt himself when was first confronted by a flow of studies and evidence of new mechanisms)

3. What Is Epigenetics? Is It Transgenerational? . TABLE 3.1 

Different Definitions of Epigenetics in a Historical Perspective (No. Definition Sources)


1 Study of the processes by which genotype gives rise to phenotype Waddinhton (1942) (cited by Wu & Morris, 2001)
2 The branch of biology which studies the causal interaction between genes and their products, which brings the genotype into being Waddington (1942) (cited by Goldberg, Allis, & Bernstein, 2007)
3 Study of the changes in gene expression which occur in organisms with differentiated cells, and the mitotic inheritance of given patterns of gene expression Holliday (1994)
4 Nuclear inheritance which is not based on differences in DNA sequence Holliday (1994)
5 The study of changes in gene function that are mitotically and/or meiotically heritable and do not entail a change in DNA sequence Wu and Morris (2001)
6 The study of stable alterations in gene expression potential that arise during development and cell proliferation Jaenisch and Bird (2003)
7 Heritable changes in gene expression that cannot be tied to genetic variation Richards (2006)
8 The study of any potentially stable and, ideally, heritable change in gene expression or cellular phenotype that occurs without changes in Watson–Crick base-pairing of DNA Goldberg et al. (2007) 9 An epigenetic trait is a stably heritable phenotype resulting from changes in a chromosome without alterations in the DNA sequence Berger, Kouzarides, Schickhattar, and Shilatifard (2009)
10 The study of the processes that underlie developmental plasticity and canalization and that bring about persistent developmental effects in both prokaryotes and eukaryotes Jablonka and Raz (2009) 11 Epigenetic inheritance … occurs when phenotypic variations that do not stem from variations in DNA base sequences are transmitted to subsequent generations of cells or organisms