Heritability and DNA Methylation

Heritability of Traits

• Heritable traits can be passed down across generations
• DNA methylation is an epigenetic mechanism where a methyl group attaches to a DNA molecule at a cytosine site

DNA Methylation

• DNA methylation can occur at the promoter region
• High methylation leads to reduced transcription, which can turn off gene expression
• DNA methylation can be catalyzed by methyltransferases
• Methylation can be passed down to offspring on the promoter region

Glucocorticoid Receptor (GR)

• The GR gene is associated with stress hormones
• DNMTs (DNA methyltransferases) are enzymes that can influence GR methylation

Mom's Grooming

• Mom's grooming affects chromatin accessibility
• High grooming leads to less methylation, allowing NGFIA to access the promoter region and de-methylate genes

Histone Remodelling

• Histone remodelling is another epigenetic mechanism
• Histones are proteins that DNA is coiled around
• Histones can change shape, influencing the structure of adjacent DNA
• Histone remodelling can upregulate or downregulate gene expression

Histones

• Histones can be modified by phosphorylation, acetylation, and methylation
• These modifications can regulate chromatin structure
• Histone deacetylase (HDAC) removes acetyl groups from histones, which can decrease gene expression
• Histone acetyltransferase (HAT) adds acetyl groups to histones, promoting gene expression

Acetyl Group

• Acetyl groups cause chromatin to open, promoting gene expression

Development of Behavioral Epigenetics

• Epigenetics is the study of all mechanisms of inheritance other than alterations to the DNA sequence
• Epigenetic changes can be influenced by environmental signals and stimuli
• Epigenetic changes can influence gene expression in specific cells
• Epigenetic changes do not involve changes to the DNA sequence itself

"Maze Bright" and "Maze Dull" Rats

• Moms who produce offspring with lower stress and anxiety levels also produce offspring with higher stress and anxiety levels in the next generation
• This demonstrates how epigenetic changes can be passed down across generations

Nervous System

• The nervous system is composed of the central nervous system and the peripheral nervous system.
• The central nervous system includes the brain and the spinal cord.
• The brain is composed of the cerebrum, cerebellum, and brainstem.
• The peripheral nervous system is composed of all nerves outside the central nervous system.
• The peripheral nervous system interacts with external and internal factors.
• The peripheral nervous system has a central nervous system and an autonomic nervous system.

Central Nervous System

• The central nervous system is responsible for processing information and coordinating bodily functions.
• The central nervous system consists of the brain and spinal cord.
• The brain serves as the control center for the body coordinating many complex functions such as movement, thought, emotion, and behavior.
• The spinal cord transmits messages to and from the brain and the rest of the body, which controls reflexes.

Peripheral Nervous System

• The peripheral nervous system consists of nerves and ganglia outside the central nervous system.
• The peripheral nervous system is responsible for carrying information to and from the central nervous system.
• The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system.
• The somatic nervous system controls voluntary movements and carries information from sensory receptors to the central nervous system.
• The autonomic nervous system controls involuntary functions, such as heart rate, breathing, and digestion. It is divided into the sympathetic and parasympathetic nervous systems.

Autonomic Nervous System

• The autonomic nervous system regulates involuntary functions, such as breathing and digestion.
• It is made up of the sympathetic nervous system and the parasympathetic nervous system.
• The sympathetic nervous system prepares your body for action, such as during an emergency or stressful situation.
• The parasympathetic nervous system promotes relaxation and conserves energy.

Blood-Brain Barrier

• The blood-brain barrier is a mechanism that protects the brain from harmful substances in the blood.
• The blood-brain barrier is formed by the tight junctions of the cells that line the blood vessels in the brain.
• The blood-brain barrier allows the passage of essential nutrients such as glucose but prevents the passage of toxins and harmful substances.

This quiz explores the heritability of traits and the role of DNA methylation as an epigenetic mechanism. It delves into how DNA methylation affects gene expression and the influence of maternal behaviors on chromatin accessibility. Additionally, it examines the enzymatic role of DNMTs in the methylation process.