Genetic Engineering & Biotechnology

Major Techniques• PCR –

• Polymerase Chain Reaction

• Restriction Endonucleases and Gel Electrophoresis

• DNA Profiling/DNA Fingerprinting

• Gene Transfer: Transformation

Outline the use of Polymerase Chain Reaction (PCR) to copy and amplify minute quantities of DNA –Specifics not required

• Used to make millions of copies of select section of DNA

• When small amount of DNA are found but large amounts are needed for analysis

• Semen, blood, other tissues, long-dead specimens – DNA from all can be amplified

• Thermus aquaticus – hot springs bacterium • http://www.dnalc.org/ddnalc.org/resources/pcr.html

STATE that in gel electrophoresis fragments of DNA move in an electric field and are separated according to their size

• Separate DNA, proteins or other molecules based on charge and size

STATE that gel electrophoresis is used in DNA Profiling/Fingerprinting

Describe the application of DNA Profiling to determine paternity and also

in forensic investigations• CSI

• Paternity

• CDC – epidemiology: disease transmission

• Geneology

• Breeding authenticity

Analyze DNA profiles to draw conclusions about paternity or forensic investigations

STATE that,

• when genes are transferred between species, the amino acid sequence of the polypeptide translated from them is UNCHANGED because the genetic code is UNIVERSAL

Outline three outcomes of the sequencing of the complete human genome

• HOMEWORK!

Organisms that have had genes transferred into them from a different

species are GMOs or Transgenic Orgs.

Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or other cell), restriction enzymes (endonucleases)

and DNA ligase

Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or other

cell), restriction enzymes (endonucleases) and DNA ligase

• Messenger RNA coded for insulin is extracted from human pancreas

• DNA copies of the messenger RNA coding for insulin are made using the enzyme reverse transcriptase.

• Plasmids: are small loops of DNA found in bacteria.

• Plasmids are cut open using restriction enzyme endonucleouse.

• The insulin gene and the plasmid are mixed.

• DNA ligase seals up the plasmid.

• The plasmid with the human insulin gene is called a recombinant plasmid.

• The recombinant plasmid are mixed with a strain of E.Coli bacteria.

• The E.coli bacteria that pick up the plasmid start to make insulin which is then extracted, purified and used by patients.

State 2 examples of the current uses of GM-crops or GM-animals

• Ex. Golden rice - produces beta-carotene, which can be metabolized into Vitamin A within the body. Scientists hope that it will eventually be a cheap source of beta-carotene in malnourished countries, reducing the number of children worldwide that go blind from Vitamin A deficiency.

• Bt maize is a genetically modified corn crop that produces a toxin that kills European corn borers feeding on the maize

GM-animal examples

GM hens - produce cancer-fighting medicines in their eggs. Human genes have been added to their DNA so that human proteins are secreted into the whites of their eggs, along with complex medicinal proteins similar to drugs used to treat skin cancer and other diseases. What exactly do these disease-fighting eggs contain? The hens lay eggs that have miR24, a molecule with potential for treating malignant melanoma and arthritis, and human interferon b-1a, an antiviral drug that resembles modern treatments for multiple sclerosis.

Strong, flexible spider silk is one of the most valuable materials in nature, and it could be used to make an array of products — from artificial ligaments to parachute cords . Researchers inserted a spiders’ dragline silk gene into the goats’ DNA in such a way that the goats would make the silk protein only in their milk. This “silk milk” could then be used to manufacture a web-like material called Biosteel.

Cats, Goats, ChickensResearchers took skin cells from Turkish Angora female cats and used a virus to insert genetic instructions for making red fluorescent protein.  What’s the point of creating a pet that doubles as a nightlight? Scientists say the ability to engineer animals with fluorescent proteins will enable them to artificially create animals with human genetic diseases

Discuss the potential benefits and possible harmful effects of one example of genetic modification

HOMEWORK

Define – Clone:

• Clone: a group of genetically identical organisms or group of organisms derived from a single parent (in nature it is called Asexual Reproduction)

Outline a technique for cloning using differentiated animal cells

• Udder cells are taken from a

donor sheep. The genes in the

cell are made dormant.

• Unfertilized eggs are taken

from another sheep.

• The nucleus is removed from

the egg cell.

• The egg cell without a nucleus

is fused with the udder cell

using a pulse of electricity.

• The fused cells develop into

zygotes.

• Inserted back into mother.

Discuss the ethical issues of Therapeutic Cloning (TC) in humans

• TC is the creation of an embryo to supply embryonic stem cells for medical use. The embryo does not survive the process…only its stem cells do.

• You should be able to discuss the ethical implications