RECOMBINANT DNA TECHNOLOGY

Chapter 13.2

GENETIC ENGINEERING

• Genetic Engineering:– Involves cutting (cleaving) DNA from one organism

into small fragments and inserting it into a host organism of the same or different species

• Also known as recombinant DNA:– Made by connecting, or recombining, fragments

of DNA from different species

Transgenic Organisms Contain Recombinant DNA

• Transgenic organisms:– Plants/animals that contain recombinant DNA

from an organism of a different genus (species)– Organism that contains “foreign” DNA• Glowing tobacco plant

Transgenic Organisms Contain Recombinant DNA

• To create a transgenic organism requires 3 steps– Isolate the foreign DNA to be inserted using a

“restriction enzyme”– Attach the DNA fragment to a “carrier”– Transfer DNA fragment via carrier into the host

organism

Transgenic Organisms Contain Recombinant DNA

• Restriction Enzyme:– Bacterial proteins that cut both strands of DNA at

a specific sequence (PALINDROME!!!)• PALINDROME: where 2 strands read the same, but in

opposite directions

• Most restriction enzymes cut short fragments of DNA and leave “sticky ends” so that the fragment will be attracted to other DNA

STICKY ENDS! THE KEY TO RESTRICTION ENZYMES

Transgenic Organisms Contain Recombinant DNA

• Vectors Transfer DNA (“the carrier”)– Vector is a means by which foreign DNA can be

carried into the host cell– Usually a bacterial cell/bacterial DNA

• Biological Vectors– Viruses and plasmids

• Mechanical Vectors– Microscopic metal bullet shot from a gene gun– micropipette

Plasmids and Bacterial Cells Produce Copies of DNA

• Clones:– Genetically identical copies of recombinant DNA• Also known as a “gene clone”

• Now, the bacterial cell starts to produce whatever protein that the recombinant DNA coded for– Human Growth Hormone– Human Insulin

Polymerase Chain Reaction (PCR)

• Method used to replicate DNA outside a host cell

• Uses heat to separate DNA strands• Makes millions of copies in less than a day

Sequencing DNA

• DNA Fingerprinting/Gel Electrophoresis– Method used by scientists to determine DNA

sequences of individuals– Strands are separated into fragments and then

separated based on size

Applications of DNA Technology

• Used in industry– Blue jean dyes– Cheese, laundry detergent, sewage treatment

• Used in Medicine– Treat human diseases, human growth hormone,

human antibodies– INSULIN PRODUCTION

• Used in Agriculture– Better tasting, stay fresh longer, protected from

disease