Download Biotechnology

Biotechnology
Spring 2013 - Althoff Reference: Mader & Windelspecht Ch. 14)
• DNA Cloning
• Recombinant
DNA
• PCR
• Analysis
• Biotechnology
Lec
21
•
•
•
By definition, __________ is the DNA Cloning
production of genetically
__________ copies of DNA,
cells, or organisms through
some __________ means.
Ex.: when a plant sends up an
underground stem or a root
sends up a new shoot, the
resulting plant is a clone of the
original plant.
Ex.: members of a bacteria
colony on petri dish are clones
because the all came from the
division of a single original cell
DNA Cloning
•
•
•
•
Reasons to clone:
a) determine the difference in base
_________ between a normal gene
and a mutated gene
b) use the genes to genetically _______
organisms in a beneficial way
When cloned genes are used to modify a
human, the process is called ______________
Otherwise, organisms are called ___________
organisms (trans = across, genic = producing).
Value of transgenic organisms – produce a
product desired by humans
Recombinant DNA Technology
•
•
Recombinant DNA
= ________
Contains DNA from
___________
different sources,
such as a human
cell and a bacterial
cell.
Recombinant DNA Technology
•
•
•
To make rDNA, one needs a _________ (i.e., a
carrier) by which the rDNA will be introduced
into a host cell
Example of a vector: ________ = small
accessory rings of DNA found in ________ that
were first discovered in E. coli. The ring in not
part of the main bacterial chromosome…and
replicates on its own.
Need 2 enzymes to introduce foreign DNA into
vector DNA:
1) a restriction enzyme which cleaves DNA
2) DNA ligase (ligo = bind)…a ‘sealer’
1
2
Polymearse Chain Reaction
•
•
•
•
•
________
Developed by Kary Mullis in 1985.
Mullis earned Nobel Prize for Chemistry in 1993
Widely used in research labs to ____________
of a segment of DNA quickly in a test tube
Process mimics DNA replication in the cell with
the exception that the PCR is very specific—it
amplifies (aka makes copies of) only a targeted
DNA sequence
PCR
•
•
•
Requires the use of
a) DNA polymerase
b) supply of nucleotides for the new
strands of DNA
The DNA polymerase used is from the bacterium
Thermus aquaticus—which lives in hot springs.
It can withstand high temperatures used to
separate the double-stranded DNA
Referred to as a chain reaction because the
targed DNA is repeatedly replicated as long as
the process continues.
Polymearse Chain Reaction
Analyzing DNA
•
•
DNA amplified (i.e., copies made) enables one
to decipher evolutionary history of organisms by
looking at mitochrondrial DNA. It can also be
used to ID a corpse to match to DNA found on
the bristles of a toothbrush.
Early analysis done using a process called ____
________________
a) a process that separates DNA fragments
according to their size
b) separation process leaves a distinctive
band that identifies a person, for
example
Analyzing DNA…con’t
•
•
•
•
Gel electrophoresis still used widely
today…including in your Genetics course (if you
continue on in Biology)
More advanced (and requiring much more
expensive equipment) is the STR Profiling
method = short tandem repeat profiling.
STR does __ require use of restriction enzymes
Newest method to produce DNA profiles or
“fingerprints” accomplished by fluorescently
labeling DNA fragments. Involves a laser
exciting the fluorescent DNA and a detector
recording the amount of emissions for each DNA
fragment
DNA “Fingerprint”
•
•
Biotechnology Products
Transgenic bacteria, plants, and animals often
now called GMOs = genetically modified
organisms.
GMO – bacteria: promote health of plants
including one that helps plant roots be protected
from some insect species. Some used to
decompose oil !!!!
•
Gene Therapy
•
Current use and
much future
potential for
application to _____
many conditions
harmful to humans