1. Chapter 12 Aultman Winter 2015
DNA Technology
Chapter 12
Aultman Winter 2015

2. Definitions
Biotechnology: the manipulation of organisms or their components to make useful products
Used for thousands of years in farming
DNA technology, techniques for
studying and manipulating genetic material,
modifying specific genes, and
moving genes between organisms.
Recombinant DNA combination of pieces of DNA from two different sources to form a single DNA molecule.
Genetic engineering, the direct manipulation of genes for practical purposes.

3. Human Insulin Insulin: Humulin:
peptide hormone produced by beta cells in the pancreas
regulates the metabolism of carbohydrates
Produced in minute quantities by humans
Deficiency  diabetes
Humulin:
Recombinant insulin
Human insulin gene transferred to bacteria or yeast
Produced in large quantities
used today by more than 4 million people with diabetes
HGH, vaccines, and other medicinal products are common

4. GM Foods
genetically modified (GM) organisms, organisms that have acquired one or more genes by artificial means.
transgenic organism contains a gene from another organism, typically of another species.
In the United States today, roughly half of the corn crop and more than three-quarters of the soybean and cotton crops are genetically modified.
Corn has been genetically modified to resist insect infestation, attack by an insect called the European corn borer.
Strawberry plants produce bacterial proteins that act as a natural antifreeze, protecting the plants from cold weather.
Potatoes and rice have been modified to produce harmless proteins derived from the cholera bacterium and may one day serve as edible vaccines.
“Golden rice 2” is a transgenic variety of rice that carries genes from daffodils and corn and could help prevent vitamin A deficiency and resulting blindness.

5. “Pharm” Animals
A transgenic pig has been produced that carries a gene for human hemoglobin, which can be isolated and used in human blood transfusions.
genetically modified pigs carried roundworm genes that produce proteins that convert less healthy fatty acids to omega-3 fatty acids
,Unlike transgenic plants, no transgenic animals are yet sold as food.

6. Recombinant DNA Techniques
To work with genes in the laboratory, biologists often use bacterial plasmids, small, circular DNA molecules that replicate separately from the larger bacterial chromosome.
carry virtually any gene,
act as vectors, DNA carriers that move genes from one cell to another, and
ideal for gene cloning, the production of multiple identical copies of a gene-carrying piece of DNA.
The polymerase chain reaction (PCR)
a technique to copy quickly and precisely a specific segment of DNA
can generate enough DNA, from even minute amounts of blood or other tissue, to allow visualization

7. A Closer Look: Cutting and Pasting DNA with Restriction Enzymes
Recombinant DNA is produced by combining two ingredients:
a bacterial plasmid and
the gene of interest.
Prepare the DNA fragments
use restriction enzymes, which cut DNA at specific nucleotide sequences (restriction sites), and
produce pieces of DNA called restriction fragments with “sticky ends” important for joining DNA from different sources.
DNA ligase connects the DNA pieces into continuous strands by forming bonds between adjacent nucleotides.

8. Obtaining the Gene of Interest
“Shotgun” approach : make every possible fragment and search for the one(s) that you want.
can yield millions of recombinant plasmids carrying many different segments of foreign DNA.
A collection of cloned DNA fragments that includes an organism’s entire genome (a complete set of its genes) is called a genomic library.
Copy a particular messenger RNA using reverse transcriptase and using an mRNA template.
Synthesize a gene of interest from scratch using an automated DNA- synthesizing machine and
Must know the sequence of amino acids or nucleotides

9. DNA profiling
used to determine if two samples of genetic material are from the same individual
compare sequences in the genome that vary from person to person
Most genes that encode enzymes are common across many taxonomic groups
From bacteria to humans: metabolism
Some regulatory sequences vary, along with other non-coding sequences
Gel Electrophoresis a method for sorting macromolecules by electrical charge and/or size.
DNA fragments are visualized as “bands” on the gel

10. Genomics the study of complete sets of genes (genomes)
more than 1,700 species have been published; more than 8,000 more are in progress
Human Genome Project
determine the nucleotide sequence of all the DNA in the human genome
identify the location and sequence of every gene
~3 billion nucleotide pairs
~21,000 genes
~98% of the human DNA was identified as noncoding

11. Genome-Mapping Techniques
whole-genome shotgun method
entire genome is chopped into fragments using restriction enzymes,
all the fragments are cloned and sequenced, and
computers running specialized mapping software reassemble the millions of overlapping short sequences into a single continuous sequence for every chromosome—an entire genome
3 billion base pairs
Cut into pieces 250 bases long  10 million pieces
Repeat several times, comparing overlap between runs

12. Proteomics
the systematic study of the full set of proteins found in organisms
when and where proteins are produced and
how they interact
Proteome: the complete set of all the proteins in a cell or organism
Composition of the proteome changes over time, and with different stages of the cell or organism’s life cycle
Predict the three-dimensional shape (tertiary structure) from the amino acid or nucleotide base sequence
X-ray crystallography
Understand and control the basic mechanisms of catalysis

13. Discussion Questions 1
Explain how DNA profiling is used in criminal trials.
Explain how recombinant DNA technology can be used to produce useful products.
Explain how recombinant DNA techniques are used to mass-produce a protein from an isolated gene.
Explain how genetic engineering is used to produce Humulin, human growth hormone, erythropoietin, vaccines, crops, and “pharm” animals.
Describe the process of cloning genes using plasmids.
Explain how the “shotgun” approach produces a genomic library.
Explain how restriction enzymes and DNA ligase are used to create recombinant DNA.

14. Discussion Questions 2
Explain how DNA profiling is used in criminal trials.
Describe the ways that DNA profiling can be used in our society.
Explain how the polymerase chain reaction (PCR), short tandem repeat (STR) analysis, restriction fragment length polymorphism (RFLP), and gel electrophoresis are used in the process of DNA profiling.
Describe the types of organisms that have been the subject of recent sequencing efforts. Explain why these particular organisms have been examined.
Describe the goals of the Human Genome Project. Explain why our genome presents a major challenge.
Explain how comparative genomics has been used to investigate acts of bioterrorism, track the spread of disease, and study evolutionary relationships.
Explain why scientists study DNA and proteins to better understand the functioning of cells and organisms.

15. Discussion Questions 3
Describe the steps used to treat severe combined immunodeficiency (SCID) using human gene therapy.
Describe the potential benefits, risks, and concerns of producing genetically modified foods.
Describe the concerns for the abuse of genetic information and technology as it relates to human society.
Describe the surprising results of DNA profiling of the human Y chromosome.