Transcript Genetic Technology PPT

Gene Technology
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Karyotyping
Genetic Engineering
Genetic Engineering in Medicine & Society
Genetic Engineering in Agriculture
Karyotyping:
a picture of your chromosomes aligned
according to size and shape starting with the longest one.
1. A karyotype is a specialized test that is done in a specific laboratory called
a Cytogenetics lab.
2. Used to determine genetic diseases: Can see missing chromosomes or
parts of chromosomes and added pieces of chromosomes or full
chromosomes. You can also see defects in the chromosomes
3. In order to analyze chromosomes, the sample must contain cells that are
actively dividing (in metaphase in mitosis)
Process of Making a Karyotype
1.
In order to study these disorders, cells from a person are grown with a
chemical that stops cell division at the metaphase stage
a. During metaphase, a chromosome exists as two chromatids
attached at the centromere.
2. The cells are stained to reveal banding patterns and placed on glass
slides.
3. The chromosomes are observed under the microscope, where
they are counted, checked for abnormalities, and photographed
4. The photograph is then enlarged, and the images of the chromosomes
are individually cut out.
5. The chromosomes are identified and arranged in homologous pairs.
1. Picture of chromosomes aligned together
Align according to size and banding patterns
http://learn.genetics.utah.edu/content/chromosomes/karyotype/
http://learn.genetics.utah.edu/content/chromosomes/karyotype/
Genetic Engineering
• Manipulation of DNA for
practical purposes
• Involves building RECOMBINANT DNA –
from 2 or more different organisms
EX: Insulin – protein hormone regulates sugar
metabolism – gene transferred to bacteria –
transcribed/translated
Steps in Genetic Engineering
1 – DNA is cut
Restriction enzymes are bacterial enzymes that
recognize and bind to specific short sequences
of DNA, then cut the DNA between specific
nucleotides within the sequences.
Vector – agent used to carry gene of interest
into another cell - plasmid
2 – Recombinant DNA is produced
Enzyme – DNA ligase – added to help
bond DNA fragments together
3 – Gene is cloned
Many copies of gene of interest are
made each time host cell reproduces
4 – Cells are screened
Each time cell reproduces - it makes a copy of
gene of interest – transcribes/translates gene
to make protein coded.
Genetic Engineering
in Medicine & Society
• Medicines
Clotting Factor VIII for Hemophilia
Growth Factors
Interleukins – HIV, cancer, immune issues
Interferons – viruses, cancer
Taxol – ovarian cancer
• Vaccines
Solution containing all /part of a harmless version of a pathogen –
immune system recognizes pathogen’s surface proteins when
injected – responds by making defensive proteins – antibodies –
combats pathogen
Gene Therapy
• Technique that involves putting a healthy copy of a gene
into the cells of a person whose copy of the gene is
defective.
• Cells are removed from patient, healthy genes are
inserted into cells, cells returned to patient’s body.
• Substance lacking is produced by cells with new genes
• Examples:
Cancer – Cystic Fibrosis
Hemophilia
Rheumatoid arthritis
DNA Fingerprinting
Gel Electrophoresis
Polymerase Chain Reaction (PCR)
• Needed to quickly make copies of DNA
• Produce billions of DNA molecules fast!
Human Genome Project
• Chromosome map reveals locations of many genes
• Improvements in diagnoses, treatments and
even cures for over 4000 genetic disorders
Genetic Engineering in Agriculture
• Crop Plants – improve favorable characteristics, yields, resistance
to pests and herbicides (potatoes-soybeans-corn)
• Growth Hormone increases milk production – weight gain in
livestock
• Risks?
Cloning
• Genetically identical
• 1997 – Scientists announced the first successful cloning
using differentiated cells – a lamb named DOLLY!
Transgenic Animals
• Cloned and used to make
proteins that are
useful in medicine
Stem Cells
• Adult (Somatic) Stem Cells;
• Adult stem cells are undifferentiated cells found throughout the body
that divide to replenish dying cells and regenerate damaged tissues
• The primary roles of adult stem cells in a living organism are to maintain
and repair the tissue in which they are found.
a. Found in tissues/organs:
b. found in Bone marrow: can generate bone, cartilage,
fat, cells that support the formation of blood, and
fibrous connective tissue. Also form all blood cells
c. adult brain: generate the brain's three major cell
STEM CELLS
• Embryonic Stem Cells
1. These cells form at the blastocyst stage of development. A
blastocyst is a hollow ball of cells that is smaller than a pinhead.
The embryonic stem cells lie within this ball of cells.
2. The undifferentiated embryonic stem cells are next stimulated to
differentiate into the desired type of cell. They make nerve cells,
heart cells, brain cells, muscle cells and other types of cells.
3. To produce differentiated cells the researchers modify the cells by
inserting specific genes