Genomics and Inheritance. What is DNA? What is DNA Day?

Genomics and Inheritance

What is DNA?

What is DNA Day?

What is DNA Day?

April 1953

Drs. James Watson and Francis Crick

determined the structure of DNA

(double helix)

April 2003

Human Genome Project determined the entire DNA

sequence of a human (3 billion letters)

What is DNA Day?

April 1953

Drs. James Watson and Francis Crick

determined the structure of DNA

(double helix)

A Genome is an entire set of an organism’s DNA

J Craig Venter Institute

The Human Genome

• 23 pairs of chromosomes



The Human Genome

Mother

Father

• 23 pairs of chromosomes

• One from your mother, one from your father



The Human Genome

Cell

DNA holds instructions for the cellDeoxyriboNucleic Acid (DNA) contains all the information

necessary to make a complete organism

DNA is composed of a combination of 4 nucleotides

DNA holds instructions for the cell

DeoxyriboNucleic Acid (DNA) contains all the information necessary to make a complete organism


A

Adenine




A T

Adenine Thymine




A T C

Adenine Thymine Cytosine




A T C G

Adenine Thymine Cytosine Guanine



A pairs with T

C pairs with G

Adenine Thymine

Cytosine Guanine



A pairs with T

C pairs with G

Which is how DNA forms a double helix.

Adenine Thymine

Cytosine Guanine

Base Pair

A T C G Nucleotides Letters

The genome is like a cookbook for the cell


A sequence of nucleotides composes a gene.

Gene Recipe



A sequence of nucleotides composes a gene.

Gene Recipe

Billions of nucleotides are packaged into chromosomes.

Genome Cookbook


Cell

Gene

Nucleotide Sequence

Refresher: What are each of these?

Refresher: What are each of these?Cell

Nucleotides

Genes Chromosome

Genome

DNA

No two genomes are the sameIndividuals differ at about .1% of their nucleotides.

Variant - A position in the genome where individuals have different nucleotides

Broad Institute

Variant



3 billion nucleotides

3 million variants

.1%



3 billion nucleotides

3 million variants

.1%

……………………………..

1 2 3 million

AGCT

AGCT

AGCT

4 choices at 3 million places 43million unique genomes

Actually, some genomes are the same

Identical twins have the same genome.


A fertilized egg splits into two identical zygotes early on.

The zygotes develop into individuals with identical genomes.


Clones have the same genome.


To clone an animal you need a body cell and an egg cell.

Body cell

Egg cellbbc.co.uk


Replace the genome of the egg cell with that of the cell to be cloned.

Body cell

Egg cell

Extract genome

Remove genome

Replace egg cell’s genome

bbc.co.uk


Place the dividing egg cell into the uterus of a foster mother.

Body cell

Egg cell

Extract genome

Remove genome

Replace egg cell’s genome

Place egg into foster mother

Clone of sheep A

bbc.co.uk

Your list of variants is your genotype

Variants

Example chromosome

Maternal

T

A

GT

C

A

.…..

….


Variants Variants

Example chromosome

Maternal Paternal

T

A

GT

C

A

.…..

….

C

A

TT

A

G

.…..

….


Variants Variants

Example chromosome

Maternal Paternal

T

A

GT

C

A

.…..

….

C

A

TT

A

G

.…..

….

Genotype

G TT TT CA AC AA G

Genotype – The variant nucleotides on both maternal and paternal chromosomes. Your genotype is unique.

M P

Genomic variants result in unique individuals

Big genomic variations allow for many different forms of life

Variations in the DNA of different individuals can cause changes in physical appearance

or can even cause disease.

Variants can result in disease

…GAG……CTC…

The A variant at position 5,248,232 on chromosome 11 causes Sickle Cell Anemia.


…GTG……CAC…

…GAG……CTC…


Variant


…GTG……CAC…

…GAG……CTC…


Sickle-shaped diseased red blood cell

Normal red blood cellVariant

Normal Disease

Uni

vers

ity o

f M

ichi

gan


A AA T TT

Genotypes observed


A AA T TT

Genotypes observed

Normal Mostly Normal Sickle Cell Anemia

microscopyu.comhttp://legacy.owensboro.kctcs.edu/micro-scopic.tumblr.com

Variant correlated to disease

microscopyu.comhttp://legacy.owensboro.kctcs.edu/micro-scopic.tumblr.com

A AA T TT Genotype

Sickle Cellcount


GenotypeA AA T TT

Sickle Cellcount


A AA T TT Genotype

Sickle Cellcount

steep slope = correlation

Variant not correlated to diseaseThe Sickle Cell A/T variant is the only variant correlated to the disease.

Any other variant is not be correlated. For example:

Chr11:119,553,795

C/A variant


Any other variant is not be correlated. For example:

Chr11:119,553,795

C/A variant

Genotype

Sickle Cellcount

C CC A AA


Any other variant will not be correlated. For example:

Chr11:119,553,795

C/A variant

C CC A AA Genotype

Sickle Cellcount

no slope = no correlation

Genome Wide Association Studies find variants correlated to disease

A AA T TT Genotype

Disease

Correlated

Not Correlated

C CC A AA Genotype

Disease


1. Pick a disease to test

2. Find individuals with and without the disease

Disease No Disease


3. Get genotypes of the individuals

4. Test variants for their correlation to disease

A AA T TTGenotype

Disease

or

C CC A AAGenotype

Disease

llllPlease PAUSE and take a momentto complete the activity

Every cell in your body has the same genome, except…

If you are a mosaic or a chimera, some cells in your body carry a different genome.

Every cell in your body has the same genome, except…

If you are a mosaic or a chimera, some cells in your body carry a different genome.

© Garland Science

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About the Scientist:

May 18, 2013UNC Student Union Great Hall

10am-12pm

Join us for the 1st annual NC DNA Day science festival to learn more about the biological and biomedical research going on in the state!

Register to attend The classroom with the most attendees will win a pizza party!

Science Art ContestCreate a painting, drawing or 3D model that embodies biomedical sciences. Prizes will be awarded! See website for more info.

ncdnaday.org/festival

Run to Support Science Outreach and Education in NC9:00 AM | Saturday, May 18th 2013

Run Through UNC Chapel Hill Campus

ncdnaday.org/5K

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Genomics and Inheritance. What is DNA? What is DNA Day?