1. Ch. 11 Genetic Technology

2. Selective Breeding
From ancient times, breeders have chosen plants and animals with the most desired traits to serve as parents of the next generation.
Breeders of plants and animals want to be sure that their populations breed consistently so that each member shows the desired trait.
Increasing the frequency of desired alleles in a population is the essence of genetic technology.

3. Inbreeding develops pure lines
Inbreeding is mating between closely related individuals. It results in offspring that are homozygous for most traits.
can bring out harmful, recessive traits because there is a greater chance that two closely related individuals both may carry a harmful recessive allele for the trait.
Horses and dogs are two examples of animals that breeders have developed as pure breeds.

4. Hybridization
hybrid is the offspring of parents that have different forms of a trait.
In the case of plants, it can lead to new “varieties” of existing plant types

5. Sometimes two different species are mated to create the desired characteristics
Only can occur between closely related species

6. Ligers are a cross between a male lion and a female tiger
Ligers are a cross between a male lion and a female tiger. They can grow to 10 feet long.

7. Beefalo are a cross between American Bison and beef cattle.

8. A Zeboid is a cross between a zebra and some other equine species.

9. Human Hybrids? There is controversy surrounding human hybrids.
Is it possible? Has it happened?

10. Several states have actually banned people from intentionally or knowingly creating a human animal-hybrid. (Arizona, Louisiana, Oklahoma, and Ohio)

12. The Ivanov Experiments
Ilya Ivanov was a Russian scientist who attempted to create a human-chimp hybrid from
All attempts were unsuccessful
In 1930 he fell out of favor with the government and was exiled to the Kazakh SSR where he died two years later.

13. Other rumored “Humanzees” include reports of experiments in China in the 1960’s and Florida in the 1920’s

14. What would a “Humanzee” look like?

15. Oliver’s Story The previous photo is of Oliver
He was thought to possibly have been a human-chimp hybrid
Later genetics testing found him to have 48 chromosomes (chimp #)
So he was a chimp!

16. http://news. nationalgeographic

18. Genetic Engineering
Genetic engineering is a faster and more reliable method for increasing the frequency of a specific allele in a population
This method involves cutting—or cleaving—DNA from one organism into small fragments and inserting the fragments into a host organism of the same or a different species.
You also may hear genetic engineering referred to as recombinant DNA technology
Recombinant DNA is made by connecting or recombining, fragments of DNA from different sources.

19. Transgenic organisms contain recombinant DNA
Plants and animals that contain functional recombinant DNA from an organism of a different genus are known as transgenic organisms because they contain foreign DNA.

20. recombinant DNA Enzymes are used to “cut and paste”
Steps involved:
Isolate a desired gene using
restriction enzymes:are bacterial proteins that have the ability to cut both strands of the DNA molecule at a specific nucleotide sequence.(the scissors doing the cut
DNA ligase “pastes” the DNA fragments together (the glue)
The result is recombinant DNA

21. Restriction enzymes cleave DNA
The same sequence of bases is found on both DNA strands, but in opposite orders. GAATTC
CTTAAG
This arrangement is called a palindrome. Palindromes are words or sentences that read the same forward and backward.
form sticky ends: single stranded ends that have a tendency to join with each other ( the key to recombinant DNA

22. Vectors transfer DNA Plasmids
vector is the means by which DNA from another species can be carried into the host cell.
may be biological or mechanical.
Biological vectors include viruses and plasmids. A plasmid, is a small ring of DNA found in a bacterial cell.
Plasmids

23. Vectors transfer DNA
Two mechanical vectors carry foreign DNA into a cell’s nucleus
One, a micropipette, is inserted into a cell; the other is a microscopic metal bullet coated with DNA that is shot into the cell from a gene gun.

24. Gene cloning Bacteria take the recombinant plasmids and reproduce
1..Isolate DNA from two sources
Gene cloning
Human cell
Plasmid
2.Cut both DNAs with the same restriction
enzyme
Bacteria take the recombinant plasmids and reproduce
This clones the plasmids and the genes they carry
Clones are genetically identical copies.
Products of the gene can then be harvested
The process of cloning a human gene in a bacterial plasmid can be divided into six steps.
3. Mix the DNAs; they join by base-pairing
4.Add DNA ligase to bond the DNA covalently
Recombinant DNA plasmid
5. Put plasmid into bacterium
6.Clone the bacterium
Bacterial clones carrying many copies of the human gene

25. Cloning of animals
Scientists are perfecting the technique for cloning animals

26. Risks To Cloning Animals
High failure rate
LOS (Large Offspring Syndrome)
Telomeric Differences (Aging Shortens Telomeres, clones can have longer or shorter telomeres)
Abnormal Gene Expression Patterns
Ethical Issues

27. Polymerase chain reaction (PCR)
method is used to amplify DNA sequences
The polymerase chain reaction (PCR) can quickly clone a small sample of DNA in a test tube
Initial DNA segment
Number of DNA molecules

28. Sequencing DNA
millions of copies of a double-stranded DNA fragment are cloned using PCR. Then, the strands are separated from each other.
The single-stranded fragments are placed in four different test tubes, one for each DNA base.
Each tube contains four normal nucleotides (A,C, G,T) and an enzyme that can catalyze the synthesis of a complementary strand.
One nucleotide in each tube is tagged with a different fluorescent color.
The reactions produce complementary strands of varying lengths.
These strands are separated according to size by gel electrophoresis producing a pattern of fluorescent bands in the gel.
The bands are visualized using a laser scanner or UV light.

29. Gel Electrophoresis sorts DNA molecules by size
Separation technique: separates DNA by size and charge
1.Restriction enzymes
cut DNA I into fragments
2. The gel
Wells made at one end. Small amounts of DNA are placed in the wells
3. The electrical field
gel placed in solution and an electrical filed is set up with one neg. (-) & one pos. (+) end
4. The fragments move
negatively charged DNA fragments travel toward positive end. The smaller fragments move faster.
Mixture of DNA molecules of different sizes
Longer molecules
Power source
Gel
Shorter molecules

30. Applications of DNA Technology
Recombinant DNA in industry
Many species of bacteria have been engineered to produce chemical compounds used by humans.
Scientists have modified the bacterium E. coli to produce the expensive indigo dye that is used to color denim blue jeans.
The production of cheese, laundry detergents, pulp and paper production, and sewage treatment have all been enhanced by the use of recombinant DNA techniques that increase enzyme activity, stability, and specificity.

31. Applications of DNA Technology
Recombinant DNA in medicine
Pharmaceutical companies already are producing molecules made by recombinant DNA to treat human diseases.
Recombinant bacteria are used in the production of human growth hormone and human insulin

32. Applications of DNA Technology
Recombinant DNA in agriculture
Crops have been developed that are better tasting, stay fresh longer, and are protected from disease and insect infestations.
The Most Common Genetically Modified (GM) Crops
“Golden rice” has been genetically modified to contain beta-carotene

33. Could GM organisms harm human health or the environment?
Genetic engineering involves some risks
Possible ecological damage from pollen transfer between GM and wild crops
Pollen from a transgenic variety of corn that contains a pesticide may stunt or kill monarch caterpillars

34. Transgenic animals :Scientists can study diseases and the role specific genes play in an organism by using transgenic animals.
Scientists can study diseases and the role specific genes play in an organism by using transgenic animals.

35. Mapping and Sequencing the Human Genome In February of 2001, the HGP published its working draft of the 3 billion base pairs of DNA in most human cells.
The Human Genome Project involves:
genetic and physical mapping of chromosomes
DNA sequencing
comparison of human genes with those of other species

36. Applications of the Human Genome Project
Improved techniques for
prenatal diagnosis of human disorders,
use of gene therapy,
development of new methods of crime detection are areas currently being researched.
diagnosis of genetic disorders.

37. Diagnosis of genetic disorders
The DNA of people with and without a genetic disorder is compared to find differences that are associated with the disorder. Once it is clearly understood where a gene is located and that a mutation in the gene causes the disorder, a diagnosis can be made for an individual, even before birth.

38. Gene therapy
the insertion of normal genes into human cells to correct genetic disorders.
Progress is slow, however
There are also ethical questions related to gene therapy

39. DNA fingerprinting STEPS~use non-coding DNA
1. Sample DNA cut with restriction enzymes
2. Fragments separated by size using gel electrophoresis
3. Fragments with highly variable regions are detected with DNA probe, revealing DNA bands of various sizes
4. The pattern of bands produced is the DNA fingerprint, which is distinguished statistically form other individuals