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Biology, Seventh Edition
Solomon • Berg • Martin
Chapter 14
DNA Technologies
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• Recombinant DNA methods
• Restriction enzymes
–Enzymes from bacteria
–Used to cut DNA molecules in specific places
–Enable researchers to cut DNA into
manageable segments
• Vector molecule carrier of DNA fragment
into cell
• Transformation: uptake of foreign DNA
into cells
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
Cutting DNA with a restriction enzyme
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• Splicing foreign DNA into a vector
• Foreign DNA and plasmid DNA cut with
same restriction enzyme
• Produces linear molecules with
complementary single-stranded ends
• Recombinant DNA created by mixing so
sticky ends pair
• DNA ligase forms covalent bonds, linking
the two fragments
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
Plasmids
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• Genomic library
• Collection of DNA fragments that
represent all the DNA in the genome
• Chromosome library
• All the DNA fragments in that specific
chromosome
• cDNA library
• Produced using reverse transcriptase
• Makes DNA copies of mature mRNA
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
Producing a
genomic or
chromosome
library
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• Genetic probes
• Segments of single-stranded DNA that
can hybridize to complementary base
sequences in target gene
• Southern blot technique
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
Using a genetic
probe to find
bacterial cells
with a specific
recombinant
DNA molecule
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• Amplifying DNA in vitro by PCR
–Small amount of double-stranded DNA
–DNA precursors
–Specific nucleic acid primers
–Taq DNA polymerase
• DNA is denatured
• Primers attach to primer-binding site on
each DNA strand
• Each strand acts as template for DNA
synthesis
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
Amplification of DNA by PCR
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• DNA sequencing
• Based on chain termination method
• Yields information about
–Structure of gene
–Probable amino acid sequences of its
encoded proteins
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
Chain termination method of DNA sequencing
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• Applications of DNA technology
• Gene therapy
• Tissue engineering
• DNA typing
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
DNA typing
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• Transgenic organisms
• Foreign DNA incorporated into their
genetic material
• Gene target
–Single gene inactivated or “knocked out”
–“Knockout mice” used in studying genes
• Mutagenesis screening
–Male mice treated with mutagens and studied
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
A transgenic
mouse
Mouse on right
is normal; mouse
on left is transgenic
animal expressing
rat growth hormone
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
Transgenic
rice
“Golden rice”
shown intermixed
with white rice
contain high
concentrations
of beta-carotene
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 14 DNA Technologies
• Safety guidelines
• Safety concerns
–Introduction of transgenic organisms
into the environment
–Health effects on humans from
consuming GM crops
• Safety measures
–Special facilities designed to hold
pathogenic organisms
–Science of risk assessment
Copyright © 2005 Brooks/Cole — Thomson Learning