Epigenetics

What is the epigenome?

DNA is wrapped around a protein called histone which are covered with chemical tags to form a second layer called the epigenome. Epigenome shapes the physical structure of the genome that tightly wraps inactive gene, making them unreadable, and relaxes active genes, making them accessible

Is the gene tightly or loosely wound around histones when a gene is active?

loosely

Are there many or few methyl molecules attached to the gene when a gene is active?

few methyl

Are there many or few acetyl molecules attached to the genes associated histone when a gene is active?

many acetyl

Are there many or few mRNA transcripts when a gene is active?

many mRNA

Is the gene tightly or loosely wound around histones when a gene is inactive?

tightly

Are there many or few methly molecules attached to the gene when a gene is inactive?

many methly

Are there many or few acetyl molecules attached to the genes associated histones when a gene is inactive?

few acetyl

Are there many or few mRNA transcripts when a gene is inactive?

few mRNA

How does epigenetics apply to cancer cells?

In many cancers, some genes are turned up and some are turned down

How does "reprogramming" work?

Erases most epigenetic tags on the parents genetic information so that the fertilized egg can develop into any type of cell

With the environment affecting the epigenome so much, how does scientists study how the environment and genes interact?

They compare genetic elements and environmental elements the determine the extent of the environmental influence

Explain how the food we eat affects gene expression

The nutrients we extract from food enter metabolic pathways where they are manipulated, modified, and molded into molecules the body can use. One such pathway is responsible for making methyl groups - important epigenetic tags that silence genes.

Familiar nutrients are key components of this methyl making pathway. Diets high in these methyl-donating nutrients can rapidly alter gene expression, especially during early development when the epigenome is first being established.

2 connections between epigenetics and human behavior

People who commit suicide have less rRNA genes than people who die of other causes. In people who commit suicide, methyl levels are higher on rRNA genes in the hippocampus. More methly means less rRNA production, which means fewer ribosomes, which means less protein production.

The gene for reelin protein has more methly (is less active) than normal in schizophrenic brains. REelin is important for shaping the brain early in development and later on for learning