Download biotechnology & genetic engineering an introduction

BIOTECHNOLOGY &
GENETIC ENGINEERING
AN INTRODUCTION
Professor Chrissie Rey
School of Molecular and Cell Biology
What is Biotechnology?
• Biotechnology can be regarded as:
– Innovation in the use of any biological substance to
make products of use to humans.
• This began in prehistory e.g breadmaking
– In a more specific sense, biotechnology refers to the
application or modification of genetically modified
(GM) organisms for improvement or enhancement in
agriculture, health or industry.
– Genetic Engineering is a means of altering a
biological organism
– Genetic Engineering of plants for e.g. is inserting a
gene (showing a particular trait e.g. fruit size) from
one source, into a plant. The source can be from
another plant, animal or human.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
WHAT IS GENETIC ENGINEERING?
• GE is the genetic manipulation of
organisms such as animals, plants or
bacteria
• This is usually achieved through
cloning (plants and bacteria) or in the
case of animals through nucleus
transfer from donor cell (parent you
wish to clone) to recipient cell (egg cell
from another parent whose nucleus has
been discarded)
WHAT IS CLONING?
DOLLY THE SHEEP: FIRST GENETICALLY
ENGINEERED OR CLONED ANIMAL
Applications of Biotechnology
• Red biotechnologies refer to medical or pharmaceutical
processes e.g. designing an organism to produce
antibodies
-
Engineering of genetic cures such as gene therapy
Disease diagnosis tools
Insulin for diabetes
Vaccines for HIV
• Green biotechnology is agricultural crop processes
• White biotechnology is industrial biotechnology e.g.
design an organism to clean up pollution or produce a
chemical
- e.g. production of chymosin from GM yeast for cheese making
• Bio-economy refers to investments and economic
output of all biotechnologies
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
BIOTECHNOLOGY FOR
AFRICA
DISEASES AND PARASITES
•
•
•
•
Malaria (mosquito control)
HIV
Hepatitis A (food borne diseases)
TB
FOOD SECURITY
•
•
•
•
Yield
Quality (nutritional value)
Pest and disease resistance
Drought resistance
BIOTECHNOLOGY FOR
GAUTENG
INDUSTRIAL
BIOTECHNOLOGY
PLANT GENETIC ENGINEERING
Neolithic humans created new plant
varieties by artificial selection
• Humans have intervened in the reproduction
and genetic makeup of plants for thousands
of years.
– Neolithic (late Stone Age) humans domesticated
virtually all of our crop species over a relatively
short period about 10,000 years ago.
• However, even for these plants, genetic modifications
began long before humans started altering crops by
artificial selection.
• For example, the wheat groups that we harvest are the
result of natural hybridizations between different
species of grasses.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Biotechnology and the food crisis
• Whatever the social and demographic
causes of human starvation around the
world, increasing food production seems like
a humane objective.
– Because land and water are the most limiting
resources for food production, the best option
will be to increase yields on available lands.
– Based on conservative estimates of population
growth, the world’s farmers will have to produce
40% more grain per hectare to feed the human
population in 2020.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Gene of interest integrated into
Agrobacterium


Plant tissue transformed

Transformed cells cultured

Plantlets grown up
Plants tested for successful
transformation (i.e. foreign gene
inserted)


Phenotypes recorded.
Genetic analysis to determine
copy number.

Crop is tested for “inserted
trait”

Comparison of GE crop with
non-GM crop

SA plant biotechnology
focus
• Primarily aimed at controlling diseases and pests.
– Insect pests.
– Virus pests.
– Fungal and bacterial diseases.
• Improving the storage properties of food.
• Improving weed control.
• Improving yield and quality of foods.
• Protecting natural resources.
• Drought and salt tolerance.
South African GM crop acreage 2003
Crop
Hectares
Percentage of total crop
White maize
58, 000
2.8%
Yellow maize
176, 000
20%
Soya
12, 000
11%
Cotton
24, 000
80%
•0.5million hectares of biotech crops grown in SA (2005):
8th in the world (world total 90 million hectares).
•Update 2006: Combined trait bollworm and herbicide (stacked)
• cotton variety now released in SA
WHO BENEFITS?
The Farmers!!!!
Average gain using Bt-cotton is
349kg/hectare@R3/ha is R1047
profit per ha
Transgenic maize growing in
South Africa
Benefits of Bt maize (2)
• Fumonisins produced by Fusarium linked to
oesophageal cancer
• Eastern Cape region in SA has one of the highest
incidences of oesophageal cancer in the world
• Associated with home grown maize (testing for
mycotoxin levels not practical)
Benefits of Bt Maize
• Bt maize controlled stalk borers with 97%
efficiency, against 75-85% efficiency from
chemical insecticides.
• Bt maize gave yield advantages on average of
10% in South Africa
• Reduction in insect attack reduces fungal
infection
Plant biotechnology has incited much
public debate
• Many people, including some scientists, are
concerned about the unknown risks associated with
the release of GM organisms into the environment.
– Much of the animosity regarding GM organisms is
political, economic, or ethical in nature, but there
are also biological concerns about GM crops.
– The most fundamental debate centers on the
extent to which GM organisms are an unknown risk
that could potentially cause harm to human health
or to the environment.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
CAN WE CLONE A HUMAN BEING?
GM FOOD –
FEAR HAS BIG EYES
CONCERNS
(Be willing to address concerns)
• Farmers
– Access
– Sustainability
– Benefit sharing
• Human Health
– Multi-drug resistance
– Allegenicity
• Environment
– Weeds
– Biodiversity
What to tell the consumer?
• General information on GM food should be
provided in a reasonable and balanced manner
• South Africa has a government-funded
programme on public understanding of
biotechnology to set the information in context
Percentage
What does the public think?
Buying response to GM food
Never buy
Not buy till
more info
Buy but get
more info
Buy
Depends
Food Labeling
Labeling should address issues of:
• Safety
• Nutrition
• Ethics (religion)
Procedures for decision
making under the GMO Act
Ag Biotechnology Product Path
Safety Assessment - Phase I
Discovery
Product
Concept
Gene
Discovery
Line Selection
Transfor
- mation
}
Safety / Registrability
Assessment



GH & Field
Evaluation
Field
Variety
Development Production
Market
}
Choice of Genes / Proteins
– trait of interest
– selectable marker
Source of Genes
– safety (history of safe use)
– ethics
Environmental / Ecological Concern
– gene
– specific crop
Line
Selection
Product Advancement
}
Post
Market
Early Allergology and Toxicology
Assessment
GO / NO GO decision
Environmental Assessment
Conclusions
• GM Food is not inherently unsafe
• Most applications facing Africa in the near term will
be for crops such as Bt maize that have already
received regulatory approval elsewhere in the world
• Data generated elsewhere are in many cases still
applicable – no need to produce a whole new data
file
• Regulators should take care to assess safety issues
objectively, not be swayed by public pressure
• Take care to focus on what you need to know, limit
the “nice to know” questions
• Safety issues should not be confused with issues of
ethics or personal choice