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Fathom.com. Chapter 9: Frontiers of Biotechnology. Manipulating Individual Genes. First, DNA must be extracted Next, DNA must be cut into pieces using restriction enzymes Then, DNA can be separated Finally, DNA can be analyzed Or, the DNA pieces can be combined for various purposes.
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Fathom.com Chapter 9: Frontiers of Biotechnology
Manipulating Individual Genes First, DNA must be extracted Next, DNA must be cut into pieces using restriction enzymes Then, DNA can be separated Finally, DNA can be analyzed Or, the DNA pieces can be combined for various purposes
Restriction Enzymes • Enzymes (proteins) used to chop up DNA at specific nucleotide sequences • The ends of the DNA that are cut are called “sticky ends” Molecular biology
Restriction Enzymes Cut DNA Gel Electrophoresis Recombinant DNA Separate DNA by size After Restriction Enzymes Chop . . .
Gel Electrophoresis • Electrophoresis is a process used to separate macromolecules such as nucleic acids and proteins according to size and charge. • Basic materials needed include a power supply, gel bed and coverage.
Steps in Gel Electrophoresis • DNA is slightly negative • The DNA fragments move through the gel towards the positive electrode • Larger pieces move more slowly through the gel • The bands on a gel indicate only the lengths of DNA fragments and do not give any information about the DNA sequences such as base pairs
Practical Applications of DNA Fingerprinting • Paternity & Maternity – Children inherit a combination of band patterns from their parents
Practical Applications cont. • Criminal Identification & Forensics – DNA isolated from blood, hair, skin cells or other genetic evidence can be compared with the DNA of a suspect
Copying DNA (see page 269-271) • Polymerase Chain Reaction (PCR) is a technique that produces millions or billions of copies of specific DNA sequence in just a few hours • Heat-resistant bacterial polymerases, DNA, and two primers are heated to unwind the two DNA strands • When the reactants are cooled, the primers bind to each strand to give the polymerases a starting point • The reactants are heated to an optimal polymerase performing temperature so that two new strands of DNA are created • Each PCR cycle doubles the number of DNA copies
Restriction Enzymes Cut DNA Gel Electrophoresis Recombinant DNA Joining a new segment to DNA After Restriction Enzymes Chop
Recombinant DNA • Recombinant DNA is DNA that contains genes from more than one organism • Involves the transfer of DNA from one organism to another • Organisms with recombinant genes may be called recombinant, transgenic, or genetically modified Nature publishing company
Neat Stuff! • The gene that makes fireflies glow has been added to this plant • Now it actually glows in the dark Prenhall
Recombinant DNA Is used to produce human insulin, clotting factors and other proteins cheaply Cloning DNA in plasmids
Genetically modified food • Genetically modified food containing pesticide, vitamin A, or resistance to weed killing chemicals is becoming more and more common. Genetically modified foods
Take this just a step further • Scientists can hybridize the genes by adding DNA from one organism to another organisms egg (meta-cloning) • This resulted in chickens that were both meaty and good egg layers Letters of Marque
How do we get these variations? Bearded Dragon Resource Exzooberance Dragon Depot
Selective Breeding This is the oldest type of genetic manipulation. Breeding organisms for a desired characteristic Works very well in plants Also works with animals, but this can be a more difficult
Pure Breed Animals • Although prized for specific qualities, purebred animals run the risk of inbreeding and developing health problems
Tay Sachs and Ashkenazi Jews There are a lot of carriers in the population of Ashkenazi Jewish people in Eastern Europe. Tay-Sachs Disease
Blue People of Kentucky • The Fugate family • Genetic disorder, autosommal recessive Methemoglobinemia
Polydactyly There is an increased incidence of the autosomal dominant disorder in the Amish population This is because of the founder effect polydactyly
Hybridization • Breeding of two different species that results in an offspring • Actually happens in nature (coydog and dogote) • Humans can do this on purpose to create desired traits, common example is the mule Real Hybrid Animals
Hybridization (continued) Liger is another example Bred for its skills and magic
The liger hybrid is more common than the tigon because the mating process is easier. The liger has both stripes and spots. The stripes are inherited from its tiger parent and the spots from the lion parent. Ligers are usually orangish/golden in color. However, there have been white tigers bred with lions to produce a very light golden coat on the offspring. If the hybrid offspring is a male, it will have a leonine mane, facial ruff of a tiger but it will not be as large and defined as a normal lion's mane. Males and females have spotted bellies an striped backs. <ale hybrids are usually infertile. Some male ligers have more mane development than others and some are almost mane-less.The liger gets most of its strength and size from both of its parents; this makes the liger possibly the largest cat in the world! On their hind legs, ligers stand approximately 12 feet tall. At most, ligers may weigh up to 1,000 pounds. Ligers make the sound of both a lion and a tiger, although their roar tends to sound more like a lion's roar.
A little game called…….is it real????? You will be shown some pictures. Use your common sense to determine whether or not these crosses are real.
There is less interest in tigons because they do not reach the same impressive size as the liger. The size and appearance depends on which subspecies are bred together. The smaller size of the tigress compared to the lion means that some or all of the cubs may be stillborn or the cubs may be born prematurely [there isn't enough space in the womb for them to develop any further] and may not survive. Premature birth can lead to health problems in those that survive. Tigons are very rare; only a few exist in the world, and even those are only held by private owners. This is because it is much more difficult to get the male tiger to mate with the female lion. Tigons look similar to ligers. They have varying stripes and spots. Tigons are also orangish in color. Male offspring may have a mane, but will be very modest. They are able to produce both lion and tiger sounds when they roar. One difference between tigons and ligers is their size. Tigons are not nearly as large as ligers. In fact, tigons are often times smaller than both of their parents. The lifespan of tigons, as well as other hybrid animals, is shorter than a normal species. The animals seem prone to cancers and other illnesses
Zebra + Fish = Zebra Fish
The mule possesses the sobriety, patience, endurance and sure-footedness of the donkey, and the vigour, strength and courage of the horse.
Zebra + __________ = A Zorse, Zonkey, & Zony
Butterfly + Sting Ray = Butterfly Ray
Lobster + Snake = Lobake
Llama + Camel = Cama
Killer Whale + Dolphin = Wholphin
Leopard + Lion = Leopon
Rhino + Bass = Rhino Bass
Clones are all around us Worth 1000 Wonderquest
Cloning • Clone is a genetically identical copy of a gene or an organism • Asexual organisms make clones of themselves • Embryo cloning: coaxing an individual cell to split as it can with identical twins naturally • Therapeutic cloning: cloning an adult’s DNA in hopes of creating tissues or organs the person can use • Reproductive cloning: cloning of an adult’s DNA in hopes of creating a genetically identical individual which can grow to adulthood CNN
Reproductive Clone Take an egg cell (stem cell) Remove the nucleus Add genetic material from another adult cell Allow the cell to divide The embryo is placed in a foster mother like in vitro fertilization to grow and be born naturally CBC News
Cloning Videos • Gaur cloning • "I cloned my pet" Introduction • Interview with Danielle and Double Trouble after cloning • Dr. Drew interview with Danielle
Stem Cells Primitive cells that give rise to other types of cells Undifferentiated- all the same Have the ability to change into other types of cells (specialized) Potential to treat many diseases, including Parkinson's, Alzheimer's, diabetes and cancer. May also be used to regenerate organs
Types of Stem Cells Embryonic stem cells from human embryos. Potential to become any type of cell (pluripotent) Fetal stem cells from aborted fetal tissue. These may not be as “pluripotent” as embryonic stem cells because they are further along in development. Umbilical or baby teeth stem cells from umbilical cords and baby teeth. These are “younger” than adult stem cells and can divide more times. They likely give rise to a greater variety of tissue types than can adult stem cells. Adult stem cells from the brain, fat, and other tissues, but adult stem cells are most commonly taken from bone marrow—particularly the iliac crest (the back of the upper hip bone).
Blastocyst ~64-128 cells
Uses In April 2001, researchers at UCLA and the University of Pittsburg found stem cells in fat sucked out of liposuction patients. In the past, stem cells were found only in bone marrow, brain tissue and fetal tissue Stem cells from fat have the ability to mature into other types of specific cells, including muscle, bone and cartilage, but how many other types is still unknown.
How it works Stem cells are injected into the area of the body being targeted for tissue regeneration As the stem cells come into contact with growth chemicals in the body, the chemicals program the stem cells to grow into the tissue surrounding it.