DNA Technology And Genetic Engineering Flashcards
DNA sequencing reveals structure of DNA?
Yes, prior to sequencing DNA must be amplified to get adequate amount.
Primers
Enable initiation of DNA synthesis
DNA polymerase
Replicates the DNA
Gel electrophoresis
Separates DNA strands by size
Nucleotides
A , G , C , T
Recombinant DNA Technology —
— Isolating and cloning genes
Recombinant DNA
— cutting, splicing, and coping DNA
Tools for manipulating DNA
— Restriction enzymes
— DNA ligases
— Plasmids
Restriction enzymes
Cut DNA at specific sites, often palindromes.
DNA ligases
Join fragments of DNA
Plasmids
Small circular pieces of DNA to which desired genes can be added and inserted into bacteria for amplification.
What is the basic idea behind genetic engineering?
The basic idea behind genetic engineering is to join DNA from two or more sources.
What does The Polymerase Chain Reaction forms part of?
Cloning DNA Fragments
Cloning DNA Fragments: The polymerase chain reaction
— used to rapidly amplify DNA sequences to obtain millions of copies;
*DNA to be amplified, primers, hear-stable DNA polymerase are combined.
*Repeated heating and cooling cycles allow for rapid amplification of a sequence of DNA defined by the primers.
Identifying the source f DNA: DNA Fingerprinting
- Often DNA sample must be amplified by PCR first.
- DNA is cut with restriction enzymes
- Different individuals will have different lengths of DNA between the restriction sites.
- DNA is separated by gel electrophoresis and fragment patterns is compared.
What kind of Transgenic Bactria have been developedI?
- Insulin
- Human growth hormone
- Erythropoietin
- Tissue plasminogen activator (tPA)
- Factor VIII (blood clotting factor needed by many haemophiliacs)
- Vaccines
What does Genetic Engineering Creates?
Transgenic Organisms (eg. Insulin, human growth hormone, etc).
Transgenic Plants
Are more vitamins and pest resistance.
Transgenic plants have been modified to express what kind of things?
- Increased resistance to freezing
- Longer shelf life
- Increased vitamin A
- Edible vaccines
- Human proteins (i.e., albumin)
- Increased resistance to pests
Bigger challenges related to Transgenic Animals?
- More difficult to introduce foreign DNA into animal cells.
- Cloning more difficult.
What are some successes in Transgenic Animals?
- Bovine growth hormone (bGH)
- Gene pharming
Bovine Growth Hormone (bGH)
Used to promote faster animal growth.
Gene pharming
Introducing human genes into rarity animals in such a way that the human protein is produced in the dairy animal’s milk.
Gene therapy
Introduction of human genes into human cells to treat or correct disease.
(For example, for ADA into patient’s T cells and reintroduce the genetically modified T cells into the patient).
Obstacles of gene therapy?
- Difficult to introduce genes into the “right” cells, where the genes would normally be expressed.
- Need effective means of delivering genes.
- Can corrective genes be introduced into reproductive cells to stop the passing of defective genes to offspring?
Retroviruses
- Human genes can be packaged in retroviruses, which can be introduce genes into human cells.
- Problems with retro viral vectors is that will only insert genes into dividing cells and insertion sited are random.
How can vectors transfer genes to human cells?
- Retroviruses
- Liposomes
- Injection naked DNA
All of these methods are experimental.
Severe combined immunodeficiency (SCID)
- Inherited disorder, lack an enzyme, adenosine deaminase (ADA)
- Deficiency of B and T cells
- Highly susceptible to infections
Cystic fibrosis
Experimentally delivering the “normal” gene in a viral vector to the recipient in a nasal spray.
*results are slightly encouraging.
Cancer
- Add genes for interleukins into cancer cells
- Incorporate gene for a foreign protein into cancer cells
- Insert genes for proteins that initiated apoptosis into cancer cells
