GN 301 Module 3: DNA Sequencing, the Human Genome Project and GINA

Dideoxyribose

Compare the structure of deoxyribose and dideoxyribose

• ==Deoxyribose== has OH on the second Carbon, while ==dideoxyribose== has a hydrogen.

Human Genome Project (1988 – 2003)

==Goals of Human Genome project:==

• to identify all the genes in the human body (estimated to be around 20,000-25,000)
• to determine the sequence of genes
• to make the information available to the public
• to address the ethics of the project

Approximately how many base pairs of DNA are in the human genome?

• 3 billion

Approximately how many genes are in the human genome?

• 20,000-25,000

Describe roles of some of the big USA players:

• ==Dept. of Energy:== interested in genetic mutations caused by power plants, so they pushed for the HGP
• ==NIH:== national institute of health, led the HGP, to research how medical health and genes were related
• ==James Watson:== second person to have his genome sequenced to encourage early detection of diseases
• ==Francis Collins==: director of the HGP, discovered genes responsible for certain genetic disorders like cystic fibrosis
• ==Celera Genomics:==
  • Craig Venter- founded Celera Genomics and sequenced the human genome using new tools he had discovered

2 approaches to gene sequencing

1. ==map-based sequencing==: divide genomes into small segments, orient those sequences with respect to each other, and then line up the pieces for sequencing
2. ==Whole genome shotgun approach:== blast the genomes into small pieces and line them up and determine the order of them with computer programs

Whose DNA was used in the original HGP?

• Two males and two females who were randomly sampled from different continents

Later Projects

==1000 genomes project (1KGP)==

• The 1000 Genomes Project is an international research consortium that was set up in 2007 with the aim of sequencing the genomes of at least 1,000 volunteers from multiple populations worldwide in order to improve our understanding of the genetic contribution to human health and disease.

==100,000 genomes project==

• The 100,000 Genomes Project was a British initiative to sequence and study the role our genes play in health and disease. Recruitment was completed in December 2018, although research and analysis is still ongoing.

Uses for DNA Sequence Data

The sequence tells scientists the kind of genetic information that is carried in a particular DNA segment.

• For example, scientists can use sequence information to determine which stretches of DNA contain genes and which stretches carry regulatory instructions, turning genes on or off.

==Orthologs vs Paralogs==

• Orthologs are genes in different organisms which are direct evolutionary counterparts of each other. Orthologs were inherited through speciation. Meanwhile, paralogs are genes in the same organism which evolved by gene duplication.

Ethics

Ethical Legal and Social Implications (ELSI)

• 5% of original HGP funding by Congress set aside for ELSI

Describe/Discuss ELSI and concerns about DNA testing and public availability of DNA sequence data

• Patent Laws: who owns the genetic information discovered?
• How reliable are the tests?
• Any regulations on genetic testing?
• How well-educated is the medical community behind the project on genomes?
• How are people in the public going to be educated so that they can make an informed choice on genetic testing?
• Is this project worth doing just to learn something, even if we don’t learn how to treat a disease?
• Will insurance coverage change based on genetic disorders?
• Can employers refuse to hire you if you have a pre-existing condition?
• Should DNA info receive special protection? (medical blood tests can detect current conditions, but genetic testing can predict future ones)

GINA

GINA stands for Genetic Info Nondiscrimination Act. Voted into law by Congress in 2007.

• Discuss provisions of GINA National law

Health insurance can’t discriminate people with genetic disorders Employers can’t discriminate against employees with genetic diseases Health insurance can’t require genetic testing No insurance protection required for life, long-term care, or disability insurance due to genetic conditions