Biotechnology

• ~~ Marriage of biology & technology ~~

• Biotechnology used in industry– Genetic Engineering– Gene Therapy– Stem Cells / Stem Cell Transplant– Genetically Modified Organisms

• food = plants / animals

Another definition of biotechnology …

• “The deliberate manipulation of DNA molecules to produce commercial products from living organisms.“– Scientists are learning how to transfer genes

from one animal, plant, or other organism into another

Importance to you …?

• Food / Crop yield

• Medicine / Health Issues

• Disease / illness – transplants

• Vaccines

• Livestock

• Law Enforcement (DNA Fingerprinting)

• Bioremediation

Mouse: Mus musculus

LE 21-3

Fertilized egg of a frog Tadpole hatching from egg

Fertilized frog eggs: one week

Restriction enzymes:

• DNA Scissors • RestrictionRestriction

Microarray – Gene Chip

Can determine thousands of different genes at one time

LE 20-8

Cathode

Powersource

Anode

Mixtureof DNAmoleculesof differ-ent sizes

Gel

Glassplates

Longermolecules

Shortermolecules

Human Gene Therapy

• Gene therapy is changing / putting in “good” genes

• Gene therapy works best when disease is caused by only one defective gene

• Vectors (viruses) are used for delivery of genes into cells

LE 20-16

Cloned gene

Retroviruscapsid

Bonemarrowcell frompatient

Inject engineeredcells into patient.

Insert RNA version of normal alleleinto retrovirus.

Viral RNA

Let retrovirus infect bone marrow cellsthat have been removed from thepatient and cultured.

Viral DNA carrying the normalallele inserts into chromosome.

Bonemarrow

Forensic Evidence

• DNA “fingerprints” from samples of body fluids or tissue can provide evidence in criminal and paternity cases

• A DNA fingerprint is a specific pattern of bands

LE 20-17Defendant’sblood (D)

Blood from defendant’sclothes

Victim’sblood (V)

Environmental Cleanup ”Bioremediation”

• Genetic engineering can be used to design bacteria to clean up oil spills

• Some bacteria can be used to degrade potentially toxic waste materials

Agricultural Applications

• DNA technology is being used to improve agricultural productivity and food quality

Animal Husbandry and “Pharm” Animals

• Transgenic organisms are made by introducing genes from one organism into the genome of another organism

• Pharmaceutical “factories,” producers of antibiotics

Safety and Ethical Questions Raised by DNA Technology

• Potential benefits of genetic engineering must be weighed against potential hazards of creating harmful products or procedures

• Most public concern is about:– genetically modified (GM) organisms

Reproductive Cloning of Mammals

• In 1997, Scotland – Dolly was the first mammal cloned (a lamb)– from a differentiated mammary cell

• Dolly’s premature death in 2003, as well as her arthritis, led to speculation that her cells were “older” than those of a normal sheep

LE 21-7

Mammarycell donor

Egg celldonor

Egg cellfrom ovary Nucleus

removedCells fusedCultured

mammary cellsare semistarved,arresting the cellcycle and causingdedifferentiation

Nucleus frommammary cell

Early embryo

Grown in culture

Implanted in uterusof a third sheep

Surrogatemother

Embryonicdevelopment

Lamb (“Dolly”) genetically identicalto mammary cell donor

• Since 1997, cloning has been demonstrated in many mammals, including:– Mice– Cats– Cows– Horses– Pigs

• “Copy Cat” was the first cat cloned

Cloning

“Copy Cat”

The Stem Cells of Animals

• A stem cell is an unspecialized (undifferentiated) cell that can reproduce itself indefinitely and differentiate into specialized cells of several types

LE 21-9

Embryonic stem cells Adult stem cells

Pluripotentcells

Totipotentcells

Culturedstem cells

Differentcultureconditions

Differenttypes ofdifferentiatedcells

Liver cells Nerve cells Blood cells

HUMAN GENOME PROJECT

Human Genome Project

• 13-year project coordinated by the U.S. Department of Energy and the NIH

• GOALS:– identify the 20,000-25,000 genes in human

DNA– determine the sequences of the 3 billion base

pairs– address the ethical, legal, and social issues

that may arise from the project.

EPIGENETICSYou are more than

your DNA

University of Utah

• http://learn.genetics.utah.edu/content/epigenetics/intro/

• http://genome.ucsc.edu/cgi-bin/hgTracks?hgS_doOtherUser=submit&hgS_otherUserName=Kate&hgS_otherUserSessionName=encodePortalSession

NIH - Epigenomics

• http://www.ncbi.nlm.nih.gov/epigenomics

Epigenome Project

• http://www.roadmapepigenomics.org/

Hox Genes

• Help lay out the basic body forms of many animals– EX: humans, flies, and worms.

• They set up the head-to-tail organization.

• You can think of them as direct instructions as an embryo develops: – “Put the head here! Legs go over there!”

Identity of Body Parts

• Drosophila has master regulatory genes called homeotic genes = HOX Genes

• Mutations to homeotic genes produce flies with strange traits, such as legs growing from the head in place of antennae

LE 21-13

Eye

AntennaLeg

Wild type Mutant

LE 21-14a

Head

Tail

Tail

Tail

Wild-type larva

Mutant larva (bicoid)

Drosophila larvae with wild-type and bicoid mutant phenotypes

Widespread Conservation of Developmental Genes Among Animals

• Analysis of the hox genes in fruit flies has shown that they all include a sequence called a homeobox

• An very similar sequence has been discovered in both vertebrates and invertebrates

LE 21-23

Adultfruit fly

Fruit fly embryo(10 hours)

Flychromosome

Mousechromosomes

Mouse embryo(12 days)

Adult mouse

LE 21-24

Thorax AbdomenGenitalsegments

Thorax Abdomen

The End