1. Human Genome Project, Epigenetics & RNAi Ms. Day/ Honors Genetics
Human Genome Project, Epigenetics & RNAi Ms. Day/ Honors Genetics

2. What is a GENOME? All our DNA of an organism= "genome”
Includes genes (2%) and “junk” DNA (98%)
also encodes rRNA and tRNA
Genes carry info for making proteins or RNAs required by body for growth and maintenance
DNA  mRNA  protein
Proteins determine
organism looks (phenotypes)
how organisms eat or fight infection
how it behaves.

3. What is the Human Genome Project (HGP)?
The international, collaborative research program
goal was the complete mapping of ALL the DNA base pairs in a human cell
3 billion base pairs long = human genome
ONLY 2% active genes; ~98% is “junk”

4. When did the HGP begin? Final HGP papers were published in 2006.
Planned in 1988
Begun formally in 1990
Coordinated by the U.S. Department of Energy (DOE) and the National Institutes of Health (NIH).
Originally planned to last 15 years, but rapid technological advances accelerated completion date to 2003.
Announced  97% finished in 2000
Final HGP papers were published in 2006.

5. Why did it take less time to complete the HGP?
Improvements in sequencing
Ex: Machines vs. people
Polymerase Chain Reaction (PCR) was developed
A method of making a lot copies of DNA so many people can work on the same piece at one time

6. Who worked on the HGP?
Established by government agencies; funded publicly.
U.S. Department of Energy (DOE) and the National Institutes of Health (NIH).
Celera Genomics is a private company whose former CEO, J. Craig Venter, ran an independent sequencing project.
Differences arose regarding who should receive the credit for this scientific milestone.
June 6, 2000
government agencies and Celera Genomics held a joint press conference to announce that TOGETHER they had completed ~97% of the human genome.

7. Who’s DNA was used? HGP does not represent any one person’s genome.
Used 4 different ethnic groups
Craig Venter of Celera Genomics has since acknowledged that his DNA was used!
Serve as a starting point for broad comparisons across humanity.
Knowledge obtained from the sequences applies to everyone because all humans share the same basic set of genes
Humans are 99.9% identical genetically

8. Why did people have reservations?
Human genome has a lot of “junk” so what is the value of sequencing it?
Is it too expensive?
HGP cost ~ $2.7 billion dollars
About $1 per base pair

9. What were the goals of the HGP?
identify all genes in human DNA
determine sequence of 3 billion bps in human DNA
store this information in databases (Ex: BLAST)
improve tools for data analysis
transfer related technologies to the private sector
to help achieve these goals, researchers also studied genetic makeup of several nonhuman organisms.
E. Coli , the fruit fly, and the mouse

10. What did they find out?
Humans have ~20,000 ACTIVE genes  much less than originally thought
The completed human sequence can now identify the proteins’ locations.
Made a physical “map” of each chromosome
Includes non-coding sequences located between genes, which makes up the vast majority of the DNA in the genome (~98%).

11. What are the benefits of the HGP?
improvements in medicine
Ex: gene therapy
- microbial genome research for fuel and environmental cleanup
- DNA forensics
- improved agriculture and livestock
- better understanding of evolution and human migration
- more accurate risk assessment

12. What is Gene Therapy?
When genes are altered (MUTATED) so that the encoded proteins are unable to carry out their normal functions  genetic disorders can result
Gene therapy is a technique for correcting defective genes
A normal gene may be inserted into a nonspecific location within the genome to replace a nonfunctional gene. This approach is most common.
Food and Drug Administration (FDA) has not yet approved any human gene therapy product for sale.
Current gene therapy is experimental and has not proven very successful in clinical trials.

13. What now?
HGP is critical for understanding human biology and disorders as well as making drugs/therapies for:
Heart disease
Breast cancer
Diabetes
Alzheimer’s disease
Cystic fibrosis
And many more…
Can help answer questions about evolution and common ancestors

14. Why is the HGP controversial?
Fairness in the use of genetic information
Who should have access to personal genetic information, and how will it be used?
Employers
Insurers
Schools
Courts
Adoption agencies
Military

15. Why is the HGP controversial?
Human responsibility
Free will versus genetic determinism
Should we “design” future children?

16. Why is the HGP controversial?
Privacy and confidentiality of genetic information
How will privacy and confidentiality managed?

17. Why is the HGP controversial?
Effects does “Gene Patenting” have on research/science
Who owns and controls genetic information?
The person (or company) who discovered it, or the person whose body it came from?
Should genetic information be the property of humanity?
Is it ethical to charge someone for access to a database of genetic information?
Will patent protection slow the advance of research and be detrimental to society as a whole in the long run?

18. Why is the HGP controversial?
Psychological impact and stigmatization due to an individual's genetic differences.
How are individuals affected if they are genetically “different”?
How are society’s perceptions and expectations of the individual affected?

19. Why is the HGP controversial?
Health and environmental issues concerning genetically modified foods (GM) and microbes.
What happens if these GM foods mutate and “take over” or outcompete natural organisms?

20. Who decides?

21. RECALL… The Central Dogma DNA  RNA  PROTEIN (polypeptide 1st)
Transcription factors are
proteins that bond to specific stretches of DNA, either stopping or initiating RNA production
Proteins can also turn off some areas of DNA permanently
DNA tightly coils around histones or molecules are added to DNA so RNA polymerase cannot access it
This does not change the genome (DNA all still there), but does change the proteome (the proteins that can be made)

22. Epigenome Epigenetics
Every cell in your body contains a complete copy of your DNA (your genome)
Different types of cells turn off different sections of DNA, which leads to your epigenome
DNA does not change, but the amount of it that can be used it less than the total, so proteome smaller
Epigenetics
the study of changes in gene activity that do not involve changes to the genetic code but still get passed down to at least one successive generation
Includes environmental factors like diet, toxins, stress and prenatal influences or histone modification (i.e.-DNA methylation)

23. What is RNA interference?
Using small pieces of mRNA called microRNA’s (miRNA’s)
mirna.html
Decreases or stops expression of a gene (DNA)
A small interfering RNA (called miRNA) is made  binds to a section of a DIFFERENT mRNA
Ribosome can NOT read codons on blocked mRNA
Protein is NOT translated

24. Blockage of translation
2. RNA interference
Can lead to degradation of an mRNA or block its translation 5
Chromatin changes
Transcription
RNA processing
mRNA
degradation
Translation
Protein processing
and degradation
Degradation of mRNA OR
Blockage of translation
Target mRNA
miRNA
Protein
complex
Dicer
Hydrogen
bond
1. micro-
RNA (miRNA)
Is made; folds back on itself. 2
2. An enzyme
(Dicer)
Cuts miRNA it into
segments.
One strand of miRNA 
Degraded; Other strand (miRNA) then
associates with proteins. 3
Bound
miRNA can base-pair with any target mRNA that contains complementary
sequence.
Ribosome is now blocked  NO translation  NO protein

25. RNAi Movie http://www.pbs.org/wgbh/nova/body/rna i.html
This movie is 15 minutes and is an EXCELLENT tutorial on RNAi 