What is biotechnology? The use of living organisms to do practical tasks. Early examples: The use of microorganisms to make cheese and wine Selective breeding of livestock and crops Production of antibiotics from microorganisms

Selective Breeding Breed only those plants or animals with desirable traits People have been using selective breeding for 1000’s of years with farm crops and domesticated animals.

Genetically modified organisms are called transgenic organisms. TRANSGENIC ANIMALS Mice – used to study human immune system Chickens – more resistant to infections Cows – increase milk supply and leaner meat 4. Goats, sheep and pigs – produce human proteins in their milk

Goal of biotechnology today: To find practical applications of DNA techniques for the improvement of human health and food production Making gene products using Genetic Engineering Medical uses. Diagnosis of disease Making vaccines and other pharmaceutical products Forensic uses of DNA such as DNA fingerprinting Agricultural uses such as making transgenic plants

DNA TECHNOLOGY DNA recombination or genetic engineering is the direct manipulation of genes for practical purposes

Recombinant DNA technology Refers to the set of techniques for combining genes from different sources in vitro( in a test tube) and transfering this DNA into a cell so it can be expressed. These techniques were first developed around 1975 and resulted in the appearance of the Biotechnology industry

Researchers can insert desired genes into plasmids, creating recombinant DNA And insert those plasmids into bacteria Bacterium 1 Plasmid isolated Cell containing gene of interest 2 DNA isolated 3 Gene inserted into plasmid Bacterial chromosome Plasmid Recombinant DNA (plasmid) DNA Gene of interest 4 Plasmid put into bacterial cell Recombinant bacterium 5 Cell multiplies with gene of interest Copies of gene Copies of protein Gene for pest resistance inserted into plants Clone of cells Protein used to make snow form at higher temperature Figure 12.1 Gene used to alter bacteria for cleaning up toxic waste Protein used to dissolve blood clots in heart attack therapy

Genetic Engineering DNA from one species is inserted into another species. Ex. Human Insulin for diabetics is now made by bacteria cells!

Therapeutic hormones In 1982, humulin, human insulin produced by bacteria Became the first recombinant drug approved by the Food and Drug Administration Figure 12.7A

Restriction enzymes cut DNA at specific sequences in the DNA Restriction enzymes = scissors

Recombinant DNA Two pieces of DNA cut with the same restriction enzyme will be able to re-combine with each other.

Plants 1) Examples of transgenic plants with resistance to viruses… potatoes, tomatoes, tobacco 2) Examples of transgenic plants with resistance to insects… corn, cotton

Animals Bacteria now produce all of the following… Human growth hormone (HGH) – Human insulin (replaced cow and pig insulin for human therapy ) Factor VIII (replaced clotting factors taken from human blood.)

Electrophoresis Separation of Negatively charged DNA molecules in an electric field. The DNA is cut by a restriction enzyme into small pieces and placed in each well of the agarose gel. The Negatively charged DNA fragments will move toward the positively charged end of the gel. The larger and longer fragments move slower than the smaller shorter fragments. This creates a pattern of DNA fragments through the gel. The gel is then stained to alllow the DNA fragment pattern to be seen. This pattern is called a DNA Fingerprint.

Gel electrophoresis sorts DNA molecules by size Gel electrophoresis sorts DNA molecules by size + – Power source Gel Mixture of DNA molecules of different sizes Longer molecules Shorter Completed gel Figure 12.10

After digestion by restriction enzymes The fragments are run through a gel – + Longer fragments Shorter x w y z 1 2 Figure 12.11B

Crime Forensic science is the use of scientific knowledge in legal situations. The DNA profile of each individual is highly specific. The chances of two people having exactly the same DNA profile is 30,000 million to 1 (except for identical twins).

DNA fingerprinting is a set of laboratory procedures DNA fingerprinting is a set of laboratory procedures That determines with near certainty whether two samples of DNA are from the same individual That has provided a powerful tool for crime scene investigators Investigator at one of the crime scenes (above), Narborough, England (left)

Example A violent murder occurred. The forensics team retrieved a blood sample from the crime scene. They prepared DNA profiles of the blood sample, the victim and a suspect as follows:

Does suspect DNA bands match DNA from the crime scene? Suspects Profile Blood sample from crime scene Victims profile

Solving Medical Problems DNA profiles can be used to determine whether a particular person is the parent of a child. A childs paternity (father) and maternity(mother) can be determined. This information can be used in Paternity suits Inheritance cases Immigration cases

Example: A Paternity Test By comparing the DNA profile of a mother and her child it is possible to identify DNA fragments in the child which are absent from the mother and must therefore have been inherited from the biological father.

Does this man’s DNA match the DNA of the child? Mother Child Man

What is cloning? Cloning is a process that can be used to produce genetically identical copies of an organism. Researchers have cloned many biological materials, including genes, cell, and entire organisms.

Do clones occur naturally? Yes. In nature, some plants and single-celled organisms, such as bacteria, produce genetically identical offspring through a process called asexual reproduction.

How are animals cloned? In reproductive cloning, researchers remove a mature somatic cell, such as a skin cell from an animal that they wish to copy. Then transfer the DNA of the donor animal's somatic cell into an egg cell, or oocyte, that has had its own DNA-containing nucleus removed.

The DNA-containing nucleus is removed from the somatic (body) cell and then injected into an empty egg cell. An electrical current is used to fuse the two and start the process of cell division.(mitosis) The egg is allowed to develop into an early-stage embryo in the test-tube and then is implanted into the womb of an adult female animal. Adult female gives birth to an animal that has the same genetic make up as the animal that donated the somatic cell.

What was Dolly? Dolly the sheep was successfully cloned in Britain in 1996 by the scientist “Ian Wilmut” and was put down in February 2003 after developing a lung infection and arthritis. Dolly the sheep became the first vertebrate cloned from the cell of an adult animal.

Human Genome Project Started 1988, finished 2001, the entire sequence of bases in human DNA is now known. This multi-national effort has led to increased knowledge of … Human genetic diseases Gene therapies Evolutionary relationships Cellular functions Cancer genes