Lecture on Nature, Nurture, and Epigenetics

Introduction

• Speaker's background as a geneticist.
• Personal story of discovering pregnancy with identical twins.
• Initial beliefs in the nature (genetic) side of the nature vs. nurture debate.

Identical Twins and the Nature vs. Nurture Debate

• Studies on identical twins raised apart highlight genetic influence on traits like IQ and criminal tendencies.
• Traits such as depression in men and political preferences more influenced by environment.
• Identical twins raised together show differences in preferences, talents, and sometimes health despite identical DNA.

Introduction to Epigenetics

• Epigenetics as a third influence besides nature and nurture.
• Explanation of DNA packaging in cells using histones and chromatin.
• Chromatin packaging restricts gene accessibility, influencing gene expression.

How Epigenetic Marks Work

• Epigenetic marks are chemical tags on chromatin affecting gene accessibility.
  • Red marks condense chromatin and turn genes off.
  • Green marks decondense chromatin and turn genes on.

Epigenetics in Embryonic Development

• Epigenetic marks are laid during embryonic development, influenced by maternal environment and behavior.
• Example: The agouti gene in mice can be turned off by certain epigenetic marks.
• Impact of maternal diet and lifestyle on offspring's health and appearance.

Transgenerational Epigenetic Inheritance

• Epigenetic marks can be passed from pregnant females to fetus and across generations.
• Study examples: Boys' pre-pubescent lifestyle choices affect their descendants' health.
• Debate and ongoing study of transgenerational inheritance in humans.

Epigenetics Post-Birth

• Epigenetic changes can occur throughout life, affecting brain development and stress response.
• Example: Rat maternal care affects offspring's stress coping abilities via epigenetic changes.

Reversibility of Epigenetic Marks

• Potential to reverse harmful epigenetic marks with drugs.
• Novel cancer treatments aim to restore normal cell function by targeting epigenetic marks.
• Promising applications for other diseases like diabetes, lupus, and neurological disorders.

Conclusion and Call to Action

• Encouragement to make healthy lifestyle choices impacting the epigenome.
• Positive lifestyle choices can benefit personal and future generations' health.
• Challenge to seize the opportunity for long-term health improvements.

End of Lecture