Chapter 31Advances in Molecular Genetics

What is a genome?• Genome: is all of an organism’s genetic

information.

Genomic map of E. coli bacteria

The Genome Project (HGP)• An international

organization called the Human Genome Organization was formed to coordinate human genome research around the world.

How has the HGP affected pharmaceutical companies?

• Drug companies are trying to apply their knowledge acquired from the HGP to develop better treatments for genetic diseases.

Other genomes under study:

Functional Genomics• It is the study of DNA sequence information to

help explain cell functions.

• It is an important tool because the DNA sequences predict the structures and functions of the proteins they encode.

Technologies

• With current methods we are now able to manipulate individual’s genes.

• Using genetic engineering, biologist can prepare recombinant DNA – DNA whose segments are from different sources.

• Recombinant DNA, once inserted into host cells, can be replicated, or cloned, to provide multiple copies of the gene for study.

What is cloning?

• Cloning is the creation of an organism that is an exact genetic copy of another. This means that every single bit of DNA is the same between the two.

2 types of Cloning:

1. Artificial embryo twinning2. Somatic Cell Nuclear Transfer

What is a stem cell?

• A stem cell is a cell whose job is not yet determined, every single cell in the body “stems” from this type of cell.

Polymerase Chain Reaction (PCR)• It is a method of producing many copies of a

tiny sample of DNA.

• Example: Forensic scientists use PCR to test samples of blood left at a crime scene.

Mutations and DNA Repair• Mutations are changes in the DNA sequence that

have many causes, including exposure to certain chemicals and radiation.

• Most mutations probably result from failure of the DNA copying and repair mechanisms to work with 100% accuracy.

Genetic Disorders and Gene Therapy• Gene therapy is the introduction of a gene into

a cell to correct a hereditary disorder.

• Some genetic disorders that that are treated by gene therapy include: some forms of diabetes, abnormally short people, Cystic Fibrosis, etc.

Ethical, Legal, and Social Issues

• The advances led by the HGP have created a situation that challenges our current legal, ethical, and social views of genetics.

Ethical, Legal, and Social Issues (cont.)• Some people argue that it is unethical to identify

healthy people who carry alleles that may predispose them to disease in the future.

• These individuals may be targeted by employers, schools, or insurance companies for discrimination.

Questions to ask yourself?

• Why would cloning be beneficial?• Why conduct stem cell research?