Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with...
-
Upload
ethan-hodge -
Category
Documents
-
view
216 -
download
0
Transcript of Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with...
![Page 1: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/1.jpg)
Genetic EngineeringCh 15
“Real World Biology”
![Page 2: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/2.jpg)
Selective Breeding
Selective BreedingPeople select organisms with desired
characteristics to produce next generationTakes advantage of naturally occurring
variation
Selective breeding of teosinte grass by native Americans 6000 years ago led to corn as we now know it
![Page 3: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/3.jpg)
Selective Breeding
HybridizationCross dissimilar organisms to
bring together best of both organismsEx: disease resistance +
increased yield
Benefits include hardier plantsAmerican botanist Luther
Burbank developed more than 800 varieties of plants using selective breeding methods.
![Page 4: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/4.jpg)
Selective Breeding
InbreedingBreeding a line of organisms with similar
characteristicsEx: dog breeds
Risks- decreased genetic variation and increased susceptibility for certain diseases/disordersEx: hip dysplasia
![Page 5: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/5.jpg)
Increasing Variation
Process used to increase the variation normally present in natureBut why?Biotechnology is the
application of a technological process, invention, or method to living organisms.
![Page 6: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/6.jpg)
Increasing variation
Can be accomplished through mutationsMutations are usually random, but can be
induced via radiation and chemical exposurePotential to yield few beneficial mutants with
desirable characteristics not found in original population
![Page 7: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/7.jpg)
Increasing Variation
Bacteria- can treat millions at a time increasing chances of producing useful mutantsEx: oil-digesting bacteria
![Page 8: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/8.jpg)
Increasing Variation
Plants-arresting chromosome separation during meiosis to produce polyploidsKnown to be more vigorous than diploid
relatives
![Page 9: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/9.jpg)
13-2 Manipulating DNA
Mutations are randomHaving a way to alter DNA in a very
specific way to achieve a particular result has huge advantages
Scientists can now use the knowledge of DNA structure and its chemical properties to study and change DNA molecules
![Page 10: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/10.jpg)
Tools of Molecular Biologists
Genetic engineering allows biologists to rewrite the DNA code of an organism
Modern techniques employed canExtracting DNA from cellsCutting it into smaller piecesIdentifying sequences of bases in DNA (genes)Making unlimited copies
![Page 11: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/11.jpg)
Finding Genes
Started with Douglas Prasher (1987) Prasher wanted to find a specific gene in a jellyfish
that codes for a molecule called green fluorescent protein, or GFP
• GFP is a natural protein that absorbs energy from light and makes parts of the jellyfish glow
Prasher thought that GFP from the jellyfish could be linked to a protein when it was being made in a cell
• bit like attaching a light bulb to that molecule
![Page 12: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/12.jpg)
Finding Genes (GFP specifically)
Prasher compared part of the amino acid sequence of the GFP protein to a genetic code tablewas able to predict a probable mRNA base sequence that
would code for this sequence of amino acids
Then used a complementary base sequence to “attract” an mRNA that matched his prediction and would bind to that sequence by base pairing. After screening a genetic “library” with thousands of different
mRNA sequences from the jellyfish, he found one that bound perfectly
![Page 13: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/13.jpg)
Finding Genes
To find the actual gene that produced GFP, Prasher took a gel in which restriction fragments from the jellyfish genome had been separated and found that one of the fragments bound tightly to the mRNAThat fragment contained the actual gene for GFP
This method is called Southern blotting, after its inventor, Edwin Southern.
![Page 14: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/14.jpg)
Finding Genes- Southern Blot Analysis
![Page 15: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/15.jpg)
Finding Genes
Today it is often quicker and less expensive for scientists to search for genes in computer databases where the complete genomes of many organisms are available.
![Page 16: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/16.jpg)
Copying DNA (specific genes)
First step is a polymerase chain reaction (PCR) Heat a piece of DNA
• separates its two strands
DNA cools and added primers bind to the single strands DNA polymerase starts copying the region between the
primers• These copies can serve as templates to make still more
copies.
![Page 17: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/17.jpg)
Polymerase Chain Reaction
Once biologists find a gene, a technique known as polymerase chain reaction (PCR) allows them to make many copies of it.
1. A piece of DNA is heated, which separates its two strands.
![Page 18: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/18.jpg)
Polymerase Chain Reaction
2. At each end of the original piece of DNA, a biologist adds a short piece of DNA that complements a portion of the sequence.
These short pieces are known as primers because they prepare, or prime, a place for DNA polymerase to start working.
![Page 19: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/19.jpg)
Polymerase Chain Reaction
3. DNA polymerase copies the region between the primers. These copies then serve as templates to make more copies.
4. In this way, just a few dozen cycles of replication can produce billions of copies of the DNA between the primers.
![Page 20: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/20.jpg)
Copying DNA
It is relatively easy to extract DNA from cells and tissues.
The extracted DNA can be cut into fragments of manageable size using restriction enzymes.
These restriction fragments can then be separated according to size, using gel electrophoresis or another similar technique
![Page 21: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/21.jpg)
Gel Electrophoresis
![Page 22: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/22.jpg)
Recombinant DNA Technology
It is a form of genetic engineering that cleaves DNA into small fragments and inserts those fragments into a host organismHost may be the same or a different species
![Page 23: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/23.jpg)
Transgenic Organisms
Organisms who have incorporated foreign DNA in their chromosomes and use this new DNA as their own
![Page 24: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/24.jpg)
How to Produce a Transgenic Organism
Step 1: Isolate the gene in the foreign DNA that you want to insertEx: isolate the gene for beta carotene in a
daffodil so you can then add it to rice
![Page 25: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/25.jpg)
Step 2: Cut it out of the chromosome (in daffodil) using restriction enzymes.
Restrictions enzymes are bacterial proteins that have the ability to cut both strands of the DNA molecule at a specific nucleotide sequence
Resulting fragments can have blunt ends or sticky ends
![Page 26: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/26.jpg)
Some Commonly used REs
EcoRI (eco r one)HindIII (hindi three)BamHI (bam h one)TaqI (tack one)
![Page 27: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/27.jpg)
Step 3: Cut host’s DNA with the same RE so cut ends will match up
When DNA from two different organisms joins up- recombinant DNA is formed
![Page 28: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/28.jpg)
VectorsGetting DNA from one organism into
another requires a vectorThe vector introduces the new DNA into the
host cell
Bacterial DNA is often used as a vector
![Page 29: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/29.jpg)
Bacterial DNA
Bacteria contains plasmids- small rings of DNA separate from the bacterium’s larger circular chromosome
The foreign DNA is inserted into the plasmid by cleaving both using the same restriction enzyme
Sticky ends match up and foreign DNA becomes part of plasmid
![Page 30: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/30.jpg)
Gene Cloning
Plasmid with foreign DNA (Now considered recombined DNA) is inserted into a bacterial cell
Plasmids can replicate within the cell and can produce up to 500 copies in the cell
![Page 31: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/31.jpg)
Soon Tons of Copies!
Bacteria clones the recombinant DNAClones-genetically identical copies
How?Bacterial cells themselves will reproduce
quickly, each with hundreds of copies of the recombinant DNA inside (plasmid + foreign DNA)
![Page 32: Genetic Engineering Ch 15 “Real World Biology”. Selective Breeding People select organisms with desired characteristics to produce next generation](https://reader036.fdocuments.net/reader036/viewer/2022062716/56649e0c5503460f94af5666/html5/thumbnails/32.jpg)
Introduction into Host Cell
Plasmid is then inserted into a host’s chromosome where it will be replicated each time the cell replicates along with the organism’s other chromosomes
The host cell can transcribe/translate that recombinant DNA into protein just like all other proteins coded in its DNA