Biotechnology and Genetic Engineering. Human Cloning-The Science In The News.
Transcript of Biotechnology and Genetic Engineering. Human Cloning-The Science In The News.
Biotechnology and Genetic Engineering
Human Cloning-The ScienceIn The News
Biotechnology
• Use of scientific & engineering principals to manipulate organisms or their genes
Products of Biotechnology
• Organisms with special biochemical, morphological, and/or growth characteristics
• Organisms that produce useful products
• Information about an organism or tissue that would other wise not be known
Classical Biotechnology
• Propagation to get selected characteristics
Plants derived from wild mustard
Techniques for Classical Biotechnology
• Selection
• Hybridization
• Mutation
Hybrid
• Offspring from crossing two genetically similar varieties of a species
• Cross between two different species
Hybrid Vigor
• Hybrid improved in certain ways over parents– Stronger– With higher yields
Important Microbiology Events
• Pasturization – Louis Pasteur (1860s)– Process to kill microorganisms that cause
fermentive change
• Germ theory– Robert Koch (late 1800s)– Germs cause infection– Developed pure culture methods
Antibiotics
• Alexander Fleming (1927)
– Mold that contaminated cultures killed bacteria
– Began process of screening for antibiotics
Molecular Biotechnology
• Manipulating genes
• Genetic recombination– Exchange of DNA sequences between
molecules
Bacterial Exchange of DNA• Transformation
• Transduction
• Conjugation
Transformation
• Donor bacterium– Lysed– Releases DNA
• Recipient bacterium– Take up DNA
• Can be induced
Transduction
• Virus transfers DNA from donor to recipient
Conjugation
• Donor & recipient make contact
• DNA is transferred
• Transfer in bacteria with plasmids
Plasmids
• Extra chromosomal pieces of DNA
• Replicate independently
• Small portion of bacteria’s DNA
• Contain genes that promote transfer
Engineering Gene Transfer
• Recombinant DNA technology
• Individual genes isolated and transferred
Applications of Biotechnology
• Producing proteins for therapeutic use
• Producing vaccines
• DNA fingerprinting
• Research on genome structure & function
• Gene therapy to treat disease
• Modification of food
Producing Therapeutic Proteins
• Insert genes into bacteria
• Manipulate bacteria to produce proteins
• Purify proteins for use
Finding the Gene of Interest• Shotgun cloning
– Isolating & purifying genomic DNA
– Cutting DNA into fragments
– Insert fragments into bacteria or yeast
– Results in complete genomic library
– Library screened to find desired gene
DNA into Gene Fragments
• DNA clipped with restriction enzymes– Recognize certain DNA sequences
Cloning Genes
• Restriction fragments into bacteria or yeast using plasmids or viruses
Complementary DNA (cDNA) Cloning
• Gene of interest is known
• Messenger RNA from gene available
• Use reverse transcriptase to make gene
• Can be expressed in bacterial systems
Gene Synthesis Cloning
• Desired sequence must be known
• Laboratory made gene inserted into yeast or bacteria
• Used for insulin cloning as example
Screening for Desired Genes
DNA Probes
• Molecule that binds to a specific gene
• Types of DNA Probe
– Molecules of RNA
– Complementary sequences of DNA
Genetically Engineered Vaccines
• Vaccines stimulate an immune response
• Benefit of genetically engineered vaccine– Non pathogenic
DNA Vaccines
• DNA sequence of pathogen injected
• Immune system develops antibodies
• Advantages – No risk of infection– No risk of illness from contamination– Long lasting immune response– Can administer many vaccines in a single shot
DNA Fingerprinting
• DNA fragments amplified
• Fragments drawn through gel
• Bands visualized by dyes
• Humans have unique patterns
Polymerase Chain Reaction(PCR)
• Makes copies of DNA fragments
• Allows for analysis starting with small samples
• Gives large number of copies
PCR can be Automated
Electrophoresis
• Separates DNA fragments
DNA Fingerprints & Paternity
Human Genome Project
• Sequence of Human DNA
• 3 billion base pairs
• 30,000 to 40,000 genes
Genomics
• Subdiscipline of genetics
• Mapping, sequencing, & analyzing
• Two areas– Structural genomics– Functional genomics
DNA Arrays (DNA Chips)• Allows screening of thousands of genes
Gene Therapy
• Uses recombinant DNA to treat genetic disorders
• Replaces defective genes
• Includes targeted gene repair
Food Modification with Biotechnology
• Increase yield
• Increase quality
• Modification of genes in organisms
• Example: transgenic plants– Genetically altered
Transgenic & Cloned Animals• Dolly
– First cloned animal– Nuclear transfer from cell to produce embryo
Transgenic & Cloned Animals
• Bioengineered animals– Combine desired traits– Cow example:
• Heavy muscle• Low fat
Genetic Engineering Controversy
• Potential dangers exist
• Experiments governed by National Institute of Health
• Genetically modified foods– Common in U.S.– Opposed by Europe
Arguments Against Bioengineering
• Long term safety of engineered foods
• Spread of bioengineered genes