Ch 9Ch 9

Gene maps and the Human Genome Project

Gene maps and the Human Genome Project

Manipulating DNA Scientists use enzymes that act as

molecular “scissors” to splice DNA. These enzymes (restriction enzymes)

come from bacteria cells! Bacteria use these enzymes to cut DNA of

viruses that invade them.

Restriction Enzymes Enzymes that cut DNA molecules at

specific nucleotide sequences. What can we use them for?

If we can cut out different fragments of DNA carrying specific genes we can also insert them into new DNA strands and modify an organism’s DNA!

http://www.youtube.com/watch?v=-sI5vy-cD2g

http://www.dnalc.org/view/15476-Mechanism-of-Recombination-3D-animation-with-with-basic-narration.html

Gel Electrophoresis DNA fragments can also be separated and

sorted according to their sizes using Gel electrophoresis. A electrical current is used DNA is loaded into a gel which has a positively

charged electrode on one end and negatively charged electrode on the other.

DNA fragments(neg charged) move towards the positive side. Smaller pieces move farther down (move more quickly)

A Restriction Map results

http://www.youtube.com/watch?v=PSwlCk_Z02c

Restriction Maps Helpful in Genetic engineering and the

study of mutations DNA strands with mutations will result in

maps with different results!

DNA Fingerprinting 1. no human is genetically identical to another unless they are identical twins2. If DNA is found at a crime scene it can be compared to a sample taken from the suspect.3. the bands on pieces of DNA can be compared to each other to find a match

Wrongful convictions overturned http://www.pbs.org/wgbh/nova/sheppard

/cleared.html

Gene Maps: Show the locations on a chromosome of

individual genes

Drosophila chromosome map

Example of gene mapping…

(not the real Y chromosome!!)

D. Gene mapping led to the Human Genome Project

E. The entire human genome was finished being mapped in June 2000 (there are more than 3 billion bases)

II.

A. Genetic testing makes it possible to determine what disorders parents might pass on to their children

B. Gene Therapy1. replacing an absent or faulty gene with a normal, working one

http://www.youtube.com/watch?v=ujf72mjy0Bg

2. high risk and experimental

3. August 2002 successful treatment by gene therapy for X-linked immunodeficiency disease also known as "bubble baby syndrome."

http://www.youtube.com/watch?v=bLI1Gfb0ynw

http://www.youtube.com/watch?v=LVKqV7a31Rs

By number, not mass!

Genetic EngineeringGenetic Engineering

a glowing transgenic tobacco plant bearing the luciferase gene of

fireflys

Dolly the cloned sheep

I. Genetic ModificationA. Altering an organism’s DNA by removing

genes or adding new onesB. Involves the use of Recombinant DNA (DNA

that contains genes from more than one organism)

C. Can be added from the same species or different ones

ex. Scientists are trying to insert a gene from cold water flounder into tomato plants to help them resist frost.

True or FalseA new finding could lead to Genetically Modified onions that don’t make us cry as we chop them. Researchers in Japan have identified the enzyme that releases a tear-duct-tickling chemical when an onion is cut. The gene that controls the production of this enzyme was isolated and can now be turned off. A GM onion lacking the enzyme would taste the same but not irritate your eyes.

TRUE!!TRUE!!

True or FalseA new genetically modified rice may save over 250 million people around the world from permanent blindness and 1-3 million from death caused by a vitamin A deficiency. A rich source of vitamin A is a chemical called beta-carotene, found in some plants like carrots. The GM rice, called “golden rice” because of its color, contains a gene from a daffodil that is inserted into the rice providing beta carotene that is converted into vitamin A in the body.

TRUE!!TRUE!!

True or FalseScientists at the American Association of Genetic Modification have identified the gene that makes blueberries blue and have put it into a strawberry. The genetically modified strawberries taste exactly the same, but are blue in color. It is hoped that this will make the fruit more appealing to children. The GM blue strawberries have been tested on children (who seem to enjoy them) during the initial trials and supermarkets are already interested.

FALSE!!FALSE!!YOU CAN NOT USE HUMANS IN THE FIRST TRIALS!!

II. Selective Breeding/Artificial selection

A. Only organisms with desired characteristics are allowed to produce another generation

Ex. Disease resistant potatoes = end to potato blight and famine

Cows that produce the most milk = more $

III. Hybridization

A. Crossing desired traits in two different organisms to create a new organism with both traits.

B. Offspring are usually sterile

Examples: a plant that produces large amounts of fruit with a plant that resists disease

A Jug: pug/jack russell

Mule: horse/donkey

a labradoodle: labrador/poodle

IV. Inbreeding

A. Maintaining desired characteristics by breeding with organisms possessing the trait. “Pure bred dogs”

B. Risks:

genetic defects due to recessive allelesgerman shepherds = bad hip joints

VI. Genetic Engineering

A. Making changes in DNA of a living organism

B. Recombinant DNA is the resultC. Transgenic – organisms that have

genes from OTHER speciesex.- Glow in the dark tobacco plants-bacteria that produce human insulin

Ruppy the first transgenic dog

Red pigment taken from sea anemones

VII. Cloning

A. An organism that is genetically identical to the donor.

Dolly the clone and her baby Bonnie

One bacteria produces a colony of clones

https://www.youtube.com/watch?v=YoEWYJHf0kU

B. The nucleus is taken out of a donor cell and put into the target egg cell who’s nucleus was removed. A zap of electricity is used to fuse it with the cytoplasm

C. Egg cell is implanted into a surrogate mother and a clone develops (p. 332)

D. Cloning stem cells creates donor organs, save endangered species

E. No genetic diversity, success rate poor (277 tries to make Dolly), expensive, health problems (Dolly had arthritis and organ failure at an early age)

https://www.youtube.com/watch?v=W4vOPaonZng

Should cloning be allowed?

http://learn.genetics.utah.edu/content/cloning/clickandclone/

Do NowWhat is one risk and one benefit

of cloning?

GMOs http://www.youtube.com/watch?

v=jAP6ZtfP9ZQ