Transgenerational Epigenetics

Epigenetics, essentially, affects how genes are read by cells, and subsequently how they produce proteins.

Epigenetics is a field where advances are being made daily. Epigenetics is defined as “heritable changes in gene expression that occur without a change in DNA sequence,” as stated by Dr. Alan Wolffe. A way in which we can understand this definition is by taking the analogy of a card game. The cards, the DNA sequence, have been dealt and will not change, however we need to understand how to play the cards, the rules, which is epigenetics. The guidelines can vary and completely change the way the card game is played and who comes out on top. The rules that are studied and understood through this research paper are those of DNA methylation and chromatin. These changes can produce

This paper will discuss how phenotypes are driven by DNA inheritance in offspring by the genes known as alleles. Each parent provides an allele although on allele is hidden in one parent and can be passed on to his or her offspring. The information presented in the monohybrid cross that shows where one parent has the hidden allele of a gene that carries the trait of orange eyes that disappears and reemerges later in the genetic make-up of an offspring. The inheritance in the offspring is driven by the DNA of that individuals parents and the genetic traits one is born with are decided by the dominant and recessive genes of his or her parents (www.nature.com, 2014).

Do the experiences or events that your parents, grandparents or even great grandparents had in the past affect your genes? Why do some humans have mental health issues and others do not? Behavioral epigenetics examines how nurture shapes nature, where nature refers to biological heredity and nurture refers to everything that occurs during the animal 's lifespan. Epigenetics is the study of alterations in an organism caused by modifications of gene expressions instead of alterations of the genetic code itself. Behavioral epigenetics is the field of study, which analyzes the role epigenetics have in shaping human or animal behavior. Epigenetics works by wrapping DNA around histone octamers to form nucleosomes. Genes will be transcribed or silenced depending on the spacing of nucleosomes, which is determined by complex processes, including post-translational modification of DNA and histones as well as the large numbers of chromatin regulatory proteins recruited to interact with these modifications (Nestler). Behavioral epigenetics explains why humans and animals behave the way they do, not by changing the DNA, but by modification of gene expression rather than alteration of the genetic code, which in turn changes behavior in multiple generations.

Epigenetics is the study of reactions that switch part of the genome at specific locations and time, and what factors influence them. A cell has a sum of signals that help on stabilizing the gene expression; these are epigenetics tags that are accumulated through cell development. While for decades scientists thought the new embryo’s epigenome was made from scratch it is now know that parents’ epigenetic tags play an important role in the life of the new creature. Most of the epigenetic tags are erased during the process of development in a process called “reprogramming” leaving the majority of the cell in a blank state though a few genes make it through the process without successful removal of the tags.

D. Steinberg (2006) that environment has the potential to alter genes as show in epigenetic studies; thereby giving credence to nurture playing a role in

By studying Epigenetics, we learn about the changes in heritable genome function without changes in the DNA sequence itself. Transgenerational inheritance requires a chromosomal or epigenetic change in the germline allowing the information to be passed on from one generation to another (Anway et al 2005a). In order for epigenetic marks to be passed down, the gametes need to conserve their epigenomes by avoiding two reprogramming events; in the gamete and zygote. It has generally been accepted that epigenetic marks are removed and re-established in the preceding generation, thus not inherited. However, studies being carried out on model organisms are challenging this concept and suggesting that this may not be entirely correct. There may be an incomplete erasure of epigenetic marks resulting in transgenerational epigenetic inheritance (Youngson and Whitelaw 2008). The present generations were being synthesised in the womb of their grandmother. Therefore, did the food my grandmother ate affect my development? Could the air we breathe affect our grandchildren? Many questions are still unknown in this field. The environment and external factors may cause additional information to be added on top of the genome resulting in phenotypic variation and disease leading to transgenerational epigenetic inheritance. Epigenetic modifications of the germline are not only important to evolutionary biologists and disease aetiology but also ecologists, as incomplete epigenetic changes can

The PBS video called “Epigenetics” brought to light some very interesting views. Through rats scientist have been able to see the works of epigenetics and believe that the finding have led to the idea that the change in genetics has the same effect on humans. The most interesting part of the video was that younger pairs of twins have very similar genes, but the older pairs of twin have more epigenetic difference in their genes. This validates the idea that the epigenetic difference in old twins is caused by environmental factors such as lifestyle choices. The idea also alludes to the idea that our parents and grandparents healthy and epigenetics may affect my heath and my children’s health. This leads to the inclination that my child’s health

Epigenetics is a fairly recent study of how the environment affects our gene expression; the word epi meaning “above”, hence epigenetics literally meaning “above genetics”. There are arguments whether or not it was lifestyle or genetics that affects our life expectancy. With epigenetics, there has been a realisation that our genes and the environment are much more closely related than previously thought. It’s some kind of middle ground.

Identical twins who are raised in different environments turn out very different as adults. One twin grows up to be a great citizen, has a job, and pays for taxes. While, the other twin grows up and goes through different route by not paying taxes and not being a model citizen. The twins have the same original DNA and have the same traits for their genetic elements but they grew up in different environments. For species are we a product of our genes or the environment, which is known as epigenetics. Epigenetics are influenced and studied by the nature vs nature, health, aging, and parental care. The primary focus of the paper is to determine how epigenetics has an impact on health, inheritance, parental care, and childhood development.

Epigenetic inheritance is different from “normal” inheritance because epigenetic inheritance inherited traits that cannot be explained by changes in a DNA sequence. For every trait, an organism receives two alleles (one from mom and one from dad.) Epigenetic inheritance goes against the idea that inheritance happens only through the DNA code that passes from parent to offspring. It means that a parent's experiences, in the form of epigenetic tags, can be passed down to future generations.

Galton, unlike the previous philosophers who have postulated nature and nurture as a “versus” battle, stated that both the nature and the nurture play a role in human development of traits. However, Galton’s line of questioning of “how much” of nature or nurture affects our trait development has also been rendered faulty, as recent research have proposed that there is a symbiotic relationship between the biological factors and environmental factors, where nature and nurture are constantly cooperating and interacting with each other to produce both biological and behavioural traits. This is a revolutionary discovery that could finally be the solution to this long-standing ‘nature vs nurture’ debate. This proposed solution is known as epigenetics.

Epigenetics can be hereditable or environmental factors that affect the expression of genes and lead to changes in gene expression. Unlike genetics, epigenetics does not only have to do with which genes are passed down to the offspring and the DNA sequence. The environmental conditions of the offspring’s parents impact the genes in their eggs and sperms by “switching on” certain genes and “switching of” others (Dowshen). Since the genes expression of the gametes are affect, the phenotypes of the offspring will change. Even in a person’s lifetime, environmental factors such as stress, chemical exposure, and diet can continue to impact gene expression through DNA methylation. During DNA methylation, a methyl group is randomly added to a 5-carbon cytosine ring, making 5-methylcytosine and these groups inhibit transcription. (Cheriyedath). Due the fact that transcription is not possible, the expressing of the genes in that section of the DNA strand will be suppressed. The attachment of the methyl group to DNA is not determined, which means that

Earlier explanations of such manifestations of TTT assumed that they were caused primarily by environmental factors, such as the parents’ child-rearing behavior (Kellermann, 2001). For many years, the prevalent notion was that children who had grown up with traumatized parents had learned to become fearful as well. New research, however, shows that transgenerational effects may be inherited also through epigenetic mechanisms (Ennis, 2014; Harper, 2005; Kellermann, 2013; Thomson, 2015; Yehuda & Bierer, 2009). An increasing number of studies are validating this claim and the term transgenerational epigenetic inheritance - TEI – has been coined to depict it (Choi & Mango, 2014).

Organisms are exposed to different kinds of environmental stresses during their life cycle. To cope up with environment assaults, plants and animals undergo some homeostasis alterations during somatic growth and heritable (transgenerational) gene expression modifications. The heritable changes can occur without any changes in base sequences and is commonly known as epigenetics. Molecular mechanisms of epigenetic modification includes DNA methylation, histone modification (methylation, acetylation, uniquitination, phosphorylation, ribosylation, and biotinylation), small RNA mediated regulation and chromatin remodeling (Wagner, 2003; Vanyushin, 2006). All of these mechanisms may be regulated by different environmental stresses. Studies have revealed altered gene expression in plants, in response to stress conditions that can be fixed epigenetically and inherited to next generation, forming epigenetic stress memories.