Epigenetics is the study of mechanisms that control which genes are switched on or off. It involves epigenetic mechanisms like methylation and histone modification that manipulate the genome without changing the DNA sequence. Experiments show that exposures like chemicals, smoking, diet, and stress during pregnancy can cause epigenetic changes that affect gene expression and traits in subsequent generations. A study in Sweden found that poor harvests and malnutrition during pregnancy were associated with higher risk of cardiovascular disease in offspring, and periods of feast after famine extended this risk to grandchildren through epigenetic inheritance. Understanding epigenetics is important for studying evolution and treating diseases like cancer, genetic disorders, immunity and neuropsychiatric conditions.

1. Epigenetics

2. • Epigenetics is the study of
mechanisms that will switch genes on
and off.
• Epigenetics Controls Genes.
• Epigenetics Is Everywhere
• Epigenetics Makes Us Unique
• Epigenetics Is Reversible

3. Analogy

4. Epigenome
Epigenome does not
represent the DNA
or genome but it
plays key role in
manipulating the
genome in order to
get the
desired/required
result

5. Epigenetic Mechanisms
• Methylation
• Genomic
imprinting
• Histone
modification

7. Epigenetic inheritance

9. Experiments and studies
• When fruit flies are exposed to certain
chemicals they get rough growths on their
eye and 13 generations are born with it too
(generations 2-13 aren't exposed to these
chemicals).
• Smoking and over-eating can cause genes for
obesity to over-express themselves and the
genes for longevity under-express
themselves.
• Pregnant women with high anxiety are known
to give birth to kids with asthma.
• Little kids who are kept very clean are at
higher risk for eczema.

10. Sweden study
• In Norrbotten, Sweden in 19th century
there were very few people. If they
had a bad harvest people would
starve.
• 1800,1812,1821,1836 an 1856 they had
bad harvest and people suffered.
• 1801,1822,1828,1844 and 1863 the
crops were good and people had
feasts.

11. • The study showed that Pregnant women who
ate poorly, tended to have children with
a higher risk of Cardiovascular diseases
when they grew older.
• Children that went from having a normal
harvest to a feast next year, were known
to have children and grandchildren with
far shorter lives. When certain socio-economic
variations were controlled it
came out to be that the future
generations would die 32 years before
their peers.

12. Importance of Epigenetics
• Study of evolution
• Epigenetic drugs to treat various
diseases.
• Cancer treatment: DNA hypomethylation
can activate oncogenes and initiate
chromosome instability, whereas DNA
hypermethylation initiates silencing of
tumor suppressor genes.
• Mental Retardation Disorders
• Immunity & Related Disorders
• Neuropsychiatric Disorders

13. Thank you.
-Padmagiri G