This document discusses epigenetics and how it relates to DNA and gene expression. It provides an overview of epigenetics, noting that epigenetics causes changes in phenotype without altering the genotype. Environmental factors like toxins, diet, and stress can prompt epigenetic changes that affect gene expression and may impact future generations. The document discusses studies on agouti mice that showed how a mother's diet could affect the fur and health of her offspring through epigenetic changes, as well as how an agricultural fungicide affected sperm counts in male rats for multiple generations. It also describes the two main epigenetic mechanisms of DNA methylation and histone modifications that can alter gene expression patterns.

1. DNA is not Destiny
Epigentics
Dennis Lloyd
Shubhda Roy

2. DNA is not Destiny
Agenda
– Overview of Epigenetics
– Environment
– Agouti Mice
– MethDataBase
– Walkthrough

3. DNA is not Destiny
Overview- Epigenetic inheritance
• Darwinian Gene Centric - evolutionary theory is limited in scope.
• Someone said “The genetic blueprint, is like a complex musical
score, remains lifeless without an orchestra of cells (players) and
epigenotypes (instruments) to express it. “
• Epigentics causes change in gene function or phenotype change
without changing the actual DNA i.e genotype.
• Historical –theory held that – each undifferentiated cell undergoes
crisis which determines its fate. This was not inherited through
genes, and was called Epigenetic.

4. DNA is not Destiny
• Hundred of cell in human body – all start out from the same point
• Liver and cells contain same DNA, but functionality is different
• This information is stored in array of chemical markers called
epigenome
• Epigenome decide the fate of a cell by switching a gene on and off
• Epigenome is the state of a cell

5. DNA is not Destiny
Environment prompts epigenetic change
• Epigentic can be caused by environment, toxins,
diet
– Plants have seasonal changes
• flowering genes silenced in cold weather
– Mother mouse licking the baby mice
– Epigentic change can effect future generation
• Agricultural fungicide - affected pregnant mother rats
-brought down sperm count of male rats – for next four
generation

6. DNA is not Destiny
Diet of inbred mice affected future generation
– Yellow fat mice known as
‘agouti mice’
– Agouti gene makes rodents
yellow, ravenous and prone to
cancer and diabetes
– Fur of baby mice varies on
methylation of agouti gene
during embryonic growth
– Pregnant mother fed a diet
rich in methyl donors(folic
acid, vitamin B12 ), small
chemical clusters attach to a
gene and turn it off.
– Baby mice brown, and lived a
long life unlike parents

7. DNA is not Destiny
Overview- Epigenetic inheritance
Epigentic factor can happen in two ways:-
DNA methylation
• Information is stored as (CH3) or methly
group tagged on a nucleotide base
• addition of methyl group to a particularbase
–interferes with chemical signaling
• Lackof (CH3) alters chromtin arrangement
leading to gene silencing after cells divide
• Too much hinders function of DNA repair
gene like tumorsuppressors, leading to
cancers

8. DNA is not Destiny
Changing spatial patternsof DNA/Histone Code
altered
• DNA wrapped around histones
• Need to unwound to be
transcribed
• physically blocking, giving
access to gene affects the
chemical signaling

9. DNA is not Destiny
• jo
MethDatabase

10. DNA is not Destiny

11. DNA is not Destiny

12. DNA is not Destiny

13. DNA is not Destiny
Alignment of Sequences Showing Potential and
Actual Methylation Sites

14. DNA is not Destiny
Density Distribution of 52 Aligned
Sequences

15. DNA is not Destiny
Thanks