Download Chapter 15: Genetic Engineering

Chapter 15:
Genetic
Engineering
Section 15-3:
Applications of Genetic
Engineering
Agriculture and Industry
 Genetic
engineering used to improve
products we get from plants and animals
 Could lead to better, less expensive, more
nutritious food, and safer manufacturing
processes
GM Crops
 Genetically
modified plants since 1996
 Example: adding bacterial genes that
produce Bt toxin - kills insects


No pesticides needed
Higher crop yields
 Resistance
to herbicides, viral infections,
rot and spoilage
 Some being made to produce plastics
GM Animals
 30%
of milk produced by cows modified
with hormones that increase milk
production
 Pigs that produce leaner meat , high
levels of omega-3
 Salmon with extra growth hormone to
make them grow quicker
 Canada – goats that produce silk
 Goat milk with antibacterial enzymes
GM Animals
 Scientists
hoping to clone transgenic
animals to increase food supply and save
endangered species
 2008 – gov’t allowed sale of meat and
milk from cloned animals
 Avoid complications of traditional
breeding, duplicate exactly
Preventing Disease
 Making
more nutritious plants
 Producing antibodies to fight disease
 Make proteins we need
Medical Research
 Transgenic
animals used as test subjects
 Study defective genes, disease
progression
 Conduct drug tests
Treating Disease
 Recombinant
DNA technology used to
make human proteins to treat disease –
human growth hormone, insulin, bloodclotting factor, cancer-fighting proteins
 Also gene therapy – the process of
changing a gene to treat a medical
disease or disorder
 Absent or faulty gene replaced with a
normal, working gene
Treating Disease
 Very
risky
 Need a more reliable way to insert
working genes
 Make sure it’s not harmful
Genetic Testing
 Hundreds
of diseases/disorders can be
tested for
 Some use labeled DNA probes that can
detect disease-causing alleles
 Some search for changes in cutting
sequences
 Some use PCR to detect differences in
length between normal and abnormal
alleles
Examining Active Genes
 Not
every gene is active in ever cell all the
time
 Understand how cells function by studying
active genes using DNA microarray
technology - measures level of activity of
genes
DNA Microarray
 Glass
slide or silicon chip to which spots of
single-stranded DNA are attached – each
spot with a different DNA fragment
 Colored tags label source of DNA
DNA Microarray

Red spots = more
cancer mRNA

Green spots =
more normal
mRNA

Yellow spots =
both
Personal Identification


No 2 individuals are
genetically identical
(except identical
twins)
Regions of
chromosomes
contain repeated
sequences that do
not code for proteins
that differ from
person to person
Personal Identification
 DNA
fingerprinting analyzes sections of
DNA that have little/no function but that
vary widely from one individual to another
 Use REs to cut DNA into fragments,
electrophoresis to separate fragments
Personal Identification
 DNA
probe detects fragments with highly
variable regions
 If enough probe/enzyme combos are
used, resulting banding pattern can be
used to distinguish a person
 DNA from any tissue can be used
Forensic Science
 Forensics
= study of crime scene
evidence
 Uses DNA fingerprinting to solve crimes,
overturn convictions
 Wildlife conservation
Establishing Relationships
 When
genes are passed parent to child,
the markers used in DNA fingerprinting are
scrambled
 Y chromosome, however, passed directly
from father to son with few changes –
paternity tests
 Pieces of mitochondrial DNA (mtDNA)
also passed from mother to child directly –
2 people with the same mtDNA share a
common maternal ancestor