Slide 1: Genetic
Engineering Changing The Living World!! By
DAVV, INDORE 1 What Is Genetic Engineering? : What Is Genetic Engineering? Directly altering/ manipulating structure and characteristic of the gene so as to manipulate biological processes and/ or organisms for the benefit of humankind
Also known as recombinant DNA technology or gene manipulation or gene cloning, means altering the genes in a living organism to produce a Genetically Modified Organism (GMO) with a new genotype
Various kinds of genetic modification are possible:
inserting a foreign gene from one species into another, forming a transgenic organism;
altering an existing gene so that its product is changed;
or changing gene expression so that it is translated more often or not at all 2 BASIC STEPS OF GENE MANIPULATION : BASIC STEPS OF GENE MANIPULATION A fragment of DNA, containing the gene to be cloned, is inserted into a circular DNA molecule called a vector, to produce a recombinant DNA or (rDNA)
transformation cassette 3 Slide 4: Transformation Cassettes Contains 4 Slide 5: 2. The vector transports the gene into a host cell, which is usually a bacterium
3. Within the host cell the vector multiplies, producing the numerous identical copies not only of itself but also of the gene it carries
4. When the host cell divides, copies of the rDNA are passed to the progeny
5. After several cell divisions, a colony of identical host cells (clone) is produced.
Each cell in the clone contains one or more copy of rDNA BASIC STEPS OF GENE MANIPULATION 5 Slide 6: The process of genetic engineering 6 Slide 7: The outcomes of genetic engineering 7 Slide 8: TOOLS OF GENETIC ENGINEERING 8 1. Resctriction enzymes : 1. Resctriction enzymes DNA cutting enzymes (molecular scissors)
Restriction endonucleases cuts DNA at a specific site defined by a sequence of bases in the DNA (recog.site) forming “sticky ends”
Eg. BamHI cuts 5' GGATCC 3' 3' CCTAGG5’
HaeIII cuts 5' GGCC 3' 3' CCGG 5'
several hundred endonucleases have been extracted from bacteria and many are used in recombinant DNA research. eg EcoR1,Hind III, HaeIII, TaqA1, Sau3A 9 2. VECTORS : 2. VECTORS Carrier of DNA (can transfers the rDNA into the host cell)
Should be small ( <10kb)
Should have an origin of replication
Could replicate in the host cell
It may be plasmid, viral genome or yeast chromosome 10 Plasmids : Plasmids Molecules of DNA that are found in bacteria
Act as a system to transfer genetic material to other bacteria, allowing those to express the transmitted genes.
small (a few thousand base pairs) & circular
usually carry only one or a few genes
have a single origin of replication
can survive in normally toxic concentrations of antibiotics
Eg. pBR322, Ti plasmid, pUC19, BAC, etc. 11 Ti Plasmid : Ti Plasmid Ti plasmid is the part of genome of Agrobacterium tumefaciens (causes Crown Gall disease in Dicot plants)
206,479 bases long
Has 196 genes, coding 195 proteins
Are natural gene vector
It carries the cry1Ac gene from the bacteria Bacillus thuringiensis to the plant cell 12 Slide 13: p standing for plasmid, B & R for Bolivar and Rodriguez
plasmid ds-DNA 4361 BP
contains a replicon region, the AmpR gene and the TcR gene
has single cleavage site for Pst I, EcoR I, Hind III, Sal I and Cla I
high copy number (20 – 30)
can insert dna fragment of size 1-5kb 13 Bacterial Artificial Chromosome (BAC) : Bacterial Artificial Chromosome (BAC) Developed by Mel Simon
Maintained in E. coli as large
single copy plasmids
Contain inserts of < 300 kb
Contain F-plasmid origin of replication
F-plasmid gene controls plasmid
replication and plasmid copy number 14 2. VIRAL DNA : 2. VIRAL DNA gene(s) of interest are incorporated into the viral genome
the cloned gene can be introduced into cells at higher frequency than by simple transformation as viruses infect cells with high efficiency
some viral vectors are specialized for producing high levels of proteins of interest
Eg. Bacterial M13 based vectors (insert of 1-4kb)
λ (lambda) phage based vectors (insert of 5-25kb) 15 YEAST ARTIFICIAL CHROMOSOME (YAC) : YEAST ARTIFICIAL CHROMOSOME (YAC) Used for cloning large DNA (200-2000kb)
Bacterial ColE1 ori and a selectable
Contains Selectable Markers
TRP1 for tryptophan biosynthesis
URA3 for uracil biosynthesis 16 Slide 17: METHODS OF INSERTING “GENE OF INTEREST” INTO THE HOST CELL 17 DNA can be inserted into cell by: : DNA can be inserted into cell by: Transformation
– Naturally competent cells
– Treat cells (E.coli, yeast, mammal cells) to make competent; soak E.coli in CaCl, mix with DNA, mild heat shock 18 Slide 19: DNA can be inserted into cell by:
– Cells with cell wall need to be
converted to protoplasts 19 Slide 20: DNA can be inserted into cell by:
– DNA is coated on tiny gold
beads and propelled into
the cells 20 Slide 21: DNA can be inserted into cells by:
– Glass pipette
punctures the cell
membrane & inserts
the DNA 21 APPLICATIONSOFGENETIC ENGINEERING : APPLICATIONSOFGENETIC ENGINEERING 22 Slide 23: To repair a genetic defect.
To enhance a natural effect e.g. growth.
To increase crop resistance to disease or climate.
To test and screen for genetically inherited diseases.
To cure disease by altering the genes.
To select human genes – embryo selection (designer babies) 23 Transgenic organisms : Transgenic organisms Organisms that contain genetic information from other species
Q: How does one do this?
A: Take a gene from one organism and place it in another
This idea has sparked the new booming industry of biotechnology 24 Slide 25: Genetic Engineering
(GMO) 25 Slide 26: 26 Slide 27: 27 Slide 28: 28 Fun With Fireflies : Fun With Fireflies There is an enzyme that makes fireflies glow
Could we take a gene out of an animal and put it in something else?
Could we get things that don’t glow, to glow?
Answer is YES 29 Glowing Tobacco Plant : Glowing Tobacco Plant Put luciferase gene in a tobacco plant and you can get a glowing tobacco plant 30 Slide 31: 31 Slide 32: 32 Glow - Fish : Glow - Fish 33 Slide 34: 34 Glow - Mice : Glow - Mice 35 Slide 36: 36 Slide 37: 37 Transgenic Microorganisms : Transgenic Microorganisms Before: Diabetics had to use insulin from cadavers
Now: We make bacteria that produce human proteins such as insulin, growth hormone, clotting factor
Future: Bacteria may produce substances to fight cancer, make raw materials for plastic and fibers 38 Recombinant Bacteria : Recombinant Bacteria Remove bacterial DNA (plasmid).
Cut the Bacterial DNA with “restriction enzymes”.
Cut the DNA from another organism with “restriction enzymes”.
Combine the cut pieces of DNA together with another enzyme and insert them into bacteria.
Reproduce the recombinant bacteria.
The foreign genes will be expressed in the bacteria. 39 Benefits of Recombinant Bacteria : Benefits of Recombinant Bacteria Bacteria can make human insulin or human growth hormone.
Bacteria can be engineered to “eat” oil spills. 40 Genetically modified organisms are called transgenic organisms. : Genetically modified organisms are called transgenic organisms. TRANSGENIC ANIMALS
Mice – used to study human immune system
Chickens – more resistant to infections
Cows – increase milk supply
4. Goats, sheep and pigs – produce human proteins in their milk 41 Transgenic Animals : Transgenic Animals There are currently no transgenic animals that are approved for human consumption.
But there are a lot of experimental studies being done 42 : Human DNA in a Goat Cell This goat contains a human gene that codes for a blood clotting agent. The blood clotting agent can be harvested in the goat’s milk. . Transgenic Goat 43 Spider Web Goats? : Spider Web Goats? Take the gene for making spider web silk 44 Slide 45: Put it in a goat
Then milk it
Extract the spider web silk in large quantities…
And we could have… 45 Slide 46: The best bullet proof vest ever!
Strong as steel cables
And much more… 46 Transgenic Plants : Transgenic Plants Already here, already controversial
Here are some facts and myths
There are only six categories of trangenic plants, approved for human consumption 47 Soy Beans : Soy Beans 50 percent of soy beans today are genetically modified 48 Corn : Corn 25 percent of corn is genetically modified 49 Insect Resistant : Insect Resistant The bulk of both soy beans and corn that is genetically modified is modified to have a natural insecticide 50 Bt - COTTON : Bt - COTTON Bt cotton – pest and insect resistant cotton
Containing cry1Ac gene form Bacillus thuringiensis 51 Flavr - savr : Flavr - savr First genetically modified fruit
With increased shelf life (upto 4-7 weeks) 52 Golden Rice : Golden Rice Rice genetically modified to have added vitamins
Not marketed to the public yet, most recent
Dr. Ingo Potrykus, 53 Slide 54: The Golden Rice Story Vitamin A deficiency is a major health problem Causes blindness
Influences severity of diarrhea, measles >100 million children suffer from the problem For many countries, the infrastructure doesn’t exist
to deliver vitamin pills Improved vitamin A content in widely consumed crops
an attractive alternative 54 Slide 55: -Carotene Pathway Problem in Plants 55 Slide 56: The Golden Rice Solution Daffodil gene Single bacterial gene;
performs both functions Daffodil gene -Carotene Pathway Genes Added 56 Herbicide resistant : Herbicide resistant Others resist weed killing chemicals 57 Transgenic Plant Myths : Transgenic Plant Myths The fish tomato and the fish berry
Genetically modify plants to have a fish gene that makes them able to live in colder temperatures
Experimentally tested, but never worked 58 Slide 59: ANIMAL CLONING 59 Clone : Clone A member of a population of genetically identical cells produced by a single cell 60 How to get a clone in 4 easy steps : How to get a clone in 4 easy steps 1. Remove the nucleus of an egg 61 How to get a clone in 4 easy steps : How to get a clone in 4 easy steps 2. Fuse egg with a cell taken from another organism
3. Place in the uterus of a foster mother
4. Foster mother gives birth to cloned baby 62 Slide 63: Donor Nucleus These two cells are fused using an electric shock. Fused Cell The fused cell begins dividing normally. Embryo The embryo is placed in the uterus of a foster mother. The embryo develops normally into a lamb—Dolly Egg Cell An egg cell is taken from an adult female sheep. The nucleus of the egg cell is removed. 63 Dolly : Dolly First time this was done in a mammal was in 1996
A gigantic scientific breakthrough at the time 64 We have also cloned : We have also cloned Cows
Monkey 65 The cutest clone : The cutest clone First cloned cat
“CC” 66 Cloned Mice : Nucleus Donor Egg Donor Surrogate Mother Cloned babies Cloned Mice 67 Female gives birth to her own dam twin! : Female gives birth to her own dam twin! Dam = female horse 68 The worlds first cloned dogs : The worlds first cloned dogs 69 The latest clones : The latest clones Will be used to study stem cells
And animal to human transplants 70 Breaking News in the Cloning World! : Breaking News in the Cloning World! Scientists just announced today that for the first time, they have successfully cloned a rhesus monkey embryo 71 Somatic Cell Therapy : Somatic Cell Therapy This is when a gene is introduced into a
patient to help them recover from a
It could be used to help those suffering
from cystic fibrosis.
Only the patient is affected and so there
are few ethical concerns. 72 Hope through Gene Therapy : 73 Hope through Gene Therapy Pros and Cons of Cloning : Pros and Cons of Cloning Pros
Saving endangered species
Transgenic animals for human consumption
Organ and tissue transplants Cons
Cloned animals have genetic defects
Health problems 74 Should we reproductively clone humans? : Should we reproductively clone humans? No!
It took 188 tries on Dolly
Success rate of 0.4% on the horse
Success rate of 1.6% on the dog
How many humans would die before this works? 75 Ethics Involving Genetic Engineering : Ethics Involving Genetic Engineering Ethical issues concerning human beings and animals
- Are we playing God?
- Religions beliefs
- Creates new viruses
- Designer Babies
Genetic Engineering and Plants
- Effects on our Environment
- Long run effects on environment 76 For further studies you can refer to: : For further studies you can refer to: Gene Cloning and DNA Analysis: An Introduction, 5th edition – T. A. Brown
Genes & Genomes: A Changing Perspective – Maxine Singer & Paul Berg 77 Slide 78: Especially to
Dr. Jyoti Bhojwani Ma’m for her encouragement, guidance and support.
And my colleagues for being so gentle and patient audience. 78