Download detailed DNA presentation

Professor Mark Krotec
Professor Juel L. Smith
Pittsburgh Tissue Engineering Initiative
• What do the letters D-N-A stand for?
Deoxyribonucleic acid
• What is the function of DNA?
Provides the instructions for our biological traits
• Where is it located in the human body?
In the cells within the nucleus
• Who were the scientist that identified DNA
structure?
Watson & Crick
• Humans are 99.9% genetically identical – only 0.1% of our genetic make-up differs.
• Our genes are remarkably similar to those of other life forms.
• 98% of our genes with chimpanzees
• 90% with mice
•
85% with zebra fish
• 21% with worms
• 7% with simple bacteria such as E. coli
•
DNA is made up of 2 individual sides (backbones) that consist of what 2 molecules?
Sugars (deoxyribose) and phosphate groups
•
The four main building blocks that make up DNA are known as?
Nucleotides aka bases
•
Name them:
adenine (A), cytosine (C), guanine (G), thymine (T)
•
These letters make up the “DNA alphabet”
•
The bases are attached directly to the backbone via covalent bonds
•
Weaker hydrogen bonds hold the bases from each side together in pairs
• These base pairs are complementary to one another
• Adenine = Thymine
• Cytosine Ξ Guanine
• The complementary strands are then referred to as antiparallel
•
Because of these bonds the 2 strands of DNA twist
Double Helix
•
•
•
•
The _________is the entirety of an organism's hereditary information
Genome
This is then broken down into fragments known as ___________
Chromosomes
An organisms chromosomes are then broken down into smaller segments known as ___________
Genes
Genome size varies from one organism to the next
• Not determined by the size of the organism
•
What organism do you think has the LARGEST genome?
• Polychaos dubium (amoeba)– 670,000,000,000 bp
•
How many base pairs make up the human genome?
• 3.2 billion bp (nearly 200 times less !!!)
• This equals approximately 25,000 genes
• 46 chromosomes (2n – diploid)
• 23 mom/23 dad
2.4 nm
The Human Genome Project is involved in determining the exact
order of the DNA bases of the entire human genome. Est. 1990
and finished in 2003.
•
•
•
6 feet (2 meters) of DNA/human cell
10 trillion cells/human body (50-70 trillion contain DNA)
So what is the total length of DNA …
3.4 nm/10 bp
(2 m of DNA/cell )(1 x 1013 cells/body) = 2 x 1013 m DNA
•
That equals ~ ? trips to the sun and back:
1Astronomical Unit = 1.5 x 1011 m
2.0 x 1013 m DNA/1.5 x 1011 m = 133.7 A U
•
That means… The DNA in your body could stretch to the sun
133 times!!!
•
It would take "about 9.5 years to read out loud (without
stopping) the more than three billion pairs of bases in one
person's genome sequence". [Source: Human Genome
Projects Information].
Measure two 20 meter lengths of thread
Stuff all 20 meters into a capsule
*** The first to complete the challenge WINS!!!!
Development & manipulation of:
• replacement tissues and organs
• artificial implants
• laboratory-grown tissues
• genetically engineered cells
• molecules to replace or support
• injured parts of the body
Why TERM?
1.
It’s HOT!
2.
It’s Relevant!
• Everybody is a potential candidate for its application
• It’s multidisciplinary, a new trend in science and education
3.
•
Based on the discovery of DNA restriction enzymes in the 1960s
•
Restriction enzymes are natural bacterial proteins
•
Recognizes and cuts a certain DNA sequence = EcoRI cuts at GAATTC
•
Recombinant DNA is made using a pair of enzymes
•
1 cuts the DNA
•
1 joins the ends of 2 DNA strands into loops
•
These loops are known as Plasmids
Restriction Enzyme
• Can be used to “Paste” together genetics
from MULTIPLE sources to create something
NEW &/or IMPROVED
Ligase
• Agriculture
• Super Crops - corn, rice, soy
• Medical
• Disease diagnosis
• Prescription medicine generation
• Stem Cell Production
• Gene therapy
• Treat or remove to make better
•
•
•
In a 4-5 day old embryo most cells are stem cells (starter cells)
ESC indefinite growth in the lab
Can be used to create all cell types
– Good tool for Transplant Therapy
• Replacement Tissue Production
Tissue Engineering (TE)
– ESC Cons:
• Come from early human embryos
Ethical Debates
• Immune rejection
– Adult stem cells not the same
• With the help of recombinant DNA technology, Induced Pluripotent Stem Cells (iPSC)
were produced
• Almost identical to embryonic stem cells, but adult based
• Indefinite growth in lab
• Can differentiate into any cell type
• Eliminate adverse immune reaction
• Gene Therapy
• Gene replacement and repair via stem cells
• Healthy = replace
• Patient = repair
**CBS News – “A ‘Holy Grail’ of Healing”