gene technology chapters 11 & 13. gene expression 0 genome 0 our complete genetic information 0...

Gene TechnologyGene Technology

Chapters 11 & 13

Gene Expression0Genome

0 Our complete genetic information

0Gene expression0 Turning parts of a chromosome “on” and “off”

Gene Expression0Uncoiled chromosomes are

called euchromatin0We have two parts to our

genes0 1. Introns

0Transcribed but not translated

0Cut out of mRNA before leaving nucleus

0 2. Exons0Transcribed and translated0Codes for a protein

http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120080/bio31.swf

Transcription0DNA mRNA0After mRNA has been made in the nucleus

0 Introns are spliced out of the mRNA0 Exons bind together0 Addition of 5’ cap and poly A tail

Gene Regulation0Similar to bacteria except out genome is much larger

and more complex098% of our DNA does not code for a protein0Each person has a specific number of non-coding

regions between exons 0 Called VNTR (Variable Number Tandem Repeats)0 Nonsense repeats in tandem

DNA Identification0Used to identify criminals

in a crime scene or to see family relation

0Four steps to use DNA identification0 1. Isolate DNA (make

copies if small sample)0 2. Cut DNA in fragments

that are known VNTR areas

0 3. Sort DNA by size (using technology)

0 4. Compare size fragments to known samples

http://www.youtube.com/watch?v=ZxWXCT9wVoI

How to Make DNA Copies0Process called PCR

0 Technology where a small DNA sample can be amplified to many copies for analysis

PCR Steps01. Add sample of DNA, DNA polymerase enzyme, free

nucleotides (to make new strands with) and heat sample0 The heat will act like helicase and separate the strands

of DNA

PCR Steps02. Cool sample down so primers can be added to DNA

template strands

PCR Steps03. DNA polymerase attaches to primers and adds

nucleotides to rest of DNA template strands

PCR Steps04. Two new strands are made repeat process until

enough DNA sample

http://www.youtube.com/watch?v=2KoLnIwoZKU

http://www.youtube.com/watch?v=eEcy9k_KsDI

Cutting DNA0Technology that cuts long

strands of DNA0Biologists use restriction

enzymes in order to cut the DNA0 Biological scissors

0Restriction enzymes can recognize specific sequences and only cut in certain areas of DNA

Cutting DNA0Sometimes when restriction enzymes cut DNA they

leave an overhang0 Creates “sticky” ends where you can then add

recombinant DNA 0 Used to input DNA from other organisms into a genome

http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120078/bio37.swf

Gel Electrophoresis0Technology that separates DNA fragments by size in a

gel to compare to known samples

Gel Electrophoresis0How to run a gel:01. DNA sample goes through restriction enzymes to

break into fragments of known VNTRs02. Each DNA sample (now cut up) gets added into its

own chamber well

Gel Electrophoresis03. Electric current is run through the gel for a specific

amount of time0 DNA is negatively charged0 End of gel is positively charged0 When current runs, the DNA fragments move towards

the end of the gel

Gel Electrophoresis04. DNA is transferred to a nylon membrane where

probes are added 0 Probes bind to complementary DNA

Gel Electrophoresis05. X-ray film exposes membrane

0 This creates a band pattern that is unique to each individual

0 Called a “bio fingerprint”0 You can create a permanent copy of results if needed to

file

Gel Electrophoresis0How to read results:

http://learn.genetics.utah.edu/content/labs/gel/

Recombinant DNA

0Genetic engineering: modifying a genome of living cell0 When you combine two

DNA strands from different organisms it is then called recombinant DNA

Cloning0Clone

0 Exact copy of DNA, a cell or an organism

0Clones can be created by inserting DNA into vectors0 Vectors are organisms that can replicate

itself 0Ex: bacteria, yeasts

Cloning01. Egg cells are extracted from one organism and the

nucleus is removed0 Nucleus removed because the DNA of the organism we

want needs to fuse into the egg

0Cells from organism we wish to clone are removed

Cloning02. Desired organisms cell is placed next to egg cell and

electric shock fuses the two cells into one0 This triggers the new embryo to begin to divide and

develop

Cloning03. Developing embryo is implanted in a surrogate

mother and after incubation period is over, a new baby organism is born with the exact same genetic information as original organism

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

http://www.youtube.com/watch?v=-Qry1gYYDCA

Vaccines0Substance containing all or part of a harmless strain

of a pathogen0 This gets introduced to our body and we build an

immunity for it creating a defense system against the pathogen called antibodies

0DNA vaccine: vaccine containing genes from pathogen but will not cause infection

http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120078/bio39.swf

http://www.youtube.com/watch?v=SduMbjW2V9A

Agricultural Applications0Made plants more tolerable to our environment

0 Resistance to weeds 0 Added genes that would be harmful to insects and pests0 Increase nutritional value to some plants0 Ex: adding vitamin A to rice in Asia

http://www.youtube.com/watch?v=FTfuAbzAeB8 – food http://www.youtube.com/watch?v=JVIznPgdQSM – animals