Epigenetic

Conrad Waddington coined the term, “epigenetic. Waddington’s concept was a pivotal concept in developmental biology as it attempted to explain how a static set of DNA sequences could dynamically give rise to a complex organism. Pioneering work by Waddington also demonstrated compelling evidence for inheritance of a seemingly acquired characteristic in drosophila fruit flies.

DNA methylation is an epigenetic mechanism used by cells to control gene expression. A number of mechanisms exist to control gene expression in eukaryotes, but DNA methylation is a commonly used epigenetic signaling tool that can fix genes in the “off ” position.

Researchers are currently looking at the links between DNA methylation and human diseases such as lupus, cancer, muscular dystrophy and various congenital defects. Their findings could be significant in aiding the development of therapies and for understanding and preventing conditions that develop during embryonic development as a result of abnormal methylation of the X chromosome and gene imprinting.

• The human genome contains 25000-35000 genes as well as switches controlling them. A genome is a complete set of DNA in a cell. DNA carries the instruction for building all the proteins that make each living creative unique.
• These 25000-35000 genes make only 5% of genome the rest consisting of switches (epigenome). As we might say we have a 100 page book & 95 pages are instructions how to read, the book.

• Much of it happens during our embryonic development.
• When you were first conceived you were just a group of few a undifferentiated embryonic stem cells, your chromatin did not have epigenetic marks/switches on it. It is only when our cells begin to divide & receive signals & information from surrounding cells that epigenetic marks begin to accumulate & genes began to turn on and off. Each cell type expresses only these genes required for its specific function. This modification is determined by the interplay between enzymes which are controlled by epigenetic signal pathways-that respond to changes in the cell’s local environment.

Perturbations of these signaling pathways can predisposed to the development of diseases such as cancer, Alzheimer, Schizophrenia says Peter Becker (2015) of Ludwig Maximilian University of Munich.

Epigenetic marks can be influenced by the environment

• The early emotional environment can lead to long lasting epigenetic changes. One example is the epigenetic changes shown in a special type of mouse AGOUTI MOUSE.
• Both mice and people have a gene called agouti (Dolinoy, Huang, & Jirtle, 2007). When a mouse’s agouti gene is completely unmethylated mouse has a yellow coat color, is obese, and prone to diabetes and cancer. When the agouti gene is methylated (as it is in normal mice) the coat color is brown and the mouse has a low disease risk. Fat yellow mice and skinny brown ones are genetically identical. The fat yellow mice look different because they have an epigenetic

• When pregnant yellow agouti mice were not fed methyl-rich foods, no folic acid –caused decreased methylation of agouti gene, thus giving birth to obese yellow mice.
• When pregnant yellow agouti mice were fed methyl-rich foods (even if they were exposed to chemicals BPA) their offsprings were brown mice.
• So these genetically identical mice look, so radically different due to epigenetic changes caused in the womb by pregnant mother ’s diet.
• Our findings provide a framework, charged messages regarding fear and anxiety also pass modified brain chemistry to their offspring” (Dias et al, 2015).

• Affectionate maternal care given to female rats pups post natally results in them giving some quality care to their offspring when they become mothers. Abusive and neglectful caregivers are known to leave children particularly susceptible to cognitive and emotional dysfunction. Indeed, there is a significant association of reported childhood maltreatment and the later diagnosis of adolescent and adulthood schizophrenia, borderline personality disorder, posttraumatic stress disorder, and major depression.
• Higher levels of care-taking behavior during the first week of life modifies gene transcription throughout the lifespan and promotes adult behavior that is characterized by stress resilience and increased maternal care.
• Researchers at the University of British Columbia have demonstrated that human infants of mothers with high levels of depression and anxiety during the third trimester have increased methylation of the Nr3c1 gene promoter in cord blood cells (Devlin, Brain, Austin, & Oberlander, 2010).

• Eat plenty of cruciferous vegetable such as broccoli and cauliflower. They contain antioxidant that enhance our tumor fighting genes and what way lower our risk of developing cancer.
• Exercise regularly. Exercise has been shown to prevent stem cells fro turning into fat cells.
• Do not suffer silently of stress, anxiety and depression. They affect negatively the epigenome. These conditions need to be dealt with as soon as they arise.

• An individual’s adult health is heavily influenced by early prenatal physiological factors affecting the mother such as food, pollution, and radiation.
• The unborn child will adjust as best it can to the external environment he/she is going to encounter upon birth by way of epigenetics changes.
• At least parts of the changed genetics code can be passed on to future generations.
• Genes don’t make you who you are. Gene expression does. And gene expression varies depending on the life you live.
• Gene activity cranks up or spins down in response to changes in your environment.
• Our social lives, our interactions with others and ourselves can change our gene expression with a rapidity, breadth, and depth previously unknown.