CLASSIC BREEDING
•  Artificially select on already-present
variation in the trait of interest
TRUNCATED SELECTION
NO BREED
BREED
f
TRAIT VALUE
A FACT
•  Molecular biology provides:
–  a means of combining genetic materials
from vastly different sources
– a means for rapid and precise
identification of genotype at different
levels of resolution
TWO DNA TECHNOLOGIES
•  Recombinant
•  Non-recombinant
RECOMBINANT DNA
•  TWO STEP METHOD:
–  Insert appropriate DNA sequence into vector
–  Insert vector into host cell
BACTERIA HARBOR TWO
ARANGEMENTS OF DNA
•  Chromosomal
•  Plasmids
GETTING INSULIN GENE
INTO VECTOR
•  STEP 1- Isolate human DNA
•  STEP 2 - Cut out insulin gene with
restriction enzymes
•  STEP 3 - Cut plasmid with same restriction
enzymes
•  STEP 4 - Glue insulin gene into plasmid
RESTRICTION ENZYMES
INSERTING A NEW GENE
TRANSGENICS
•  Organisms that contain new DNA from
other organisms
(often different taxa).
HOW TO INSERT TRANSGENES
•  Microinjection: insects, fish mammals
fertizilized eggs
•  Biolistics: bombard plant tissue culture with
DNA-coated particles
•  Sperm-mediated: coat(rodent, chicken)
sperm with DNA vectors
•  Virus: expose embryos to retrovirus
HOW TO INSERT TRANSGENES
•  ….
TRANSGENIC MAMMALS
•
•
•
•
•
•
Mice – human genetic disorders
Marmosets – human disorders
Goats - Biosteel
Pigs – Enviropig
Cattle – Herman The Bull
Dogs – Ruppy (ruby glow)
WORLD’S FIRST
TRANSGENIC PET
•  ,,,
Franken Foods?
MISTRUST
CONCERNS REGARDING
GMO’S
•  New background, new expression
•  Expression throughout the organism
•  Constant or increased deployment
of pesticides
•  Transfer of genes to pests
•  Dangers faced by monocrops
•  Wrong focus
NON-RECOMBINANT
METHODS
•  DNA technology that does not require
recombination of DNA into another
organism
PCR
•  Polymerase Chain Reaction
PCR AT WORK
1
HEAT
2
3
4
DNA POLYMERASE
COOL A BIT
HEAT
A FACT
•  DNA consists of coding regions (genes) and
non-coding regions
•  Some non-coding regions consist of many
repeats of short sequences i.e. Short Tandem
Repeats
•  The number of repeats at a given site varies
among individuals but are more similar
within lineages
STR ANALYSIS
•  Compare the lengths of STR’s among
individuals
ANOTHER FACT
•  Since the DNA fragments are negatively
charged, they will move through a porous
gel via electric current at size-dependent
rates
DNA PROBE
•  A single strand of a particular sequence of
nucleotide bases that is complementary to
the fragment being sought A FACT
•  Adding a restriction enzyme to pool of
DNA will give you many different
restriction fragments of different sizes
RFLP 4- STEP PROCESS
•  ISOLATE DNA
•  CUT USING ENZYMES
•  SEPARATE UNDER CURRENT
•  IDENTIFY USING PROBES
A FACT
•  The length of particular restriction
fragments can be highly variable
RESTRICTION FRAGMENT LENGTH
POLYMORPHISM - RFLP
SOME QUESTIONS FOR GF
TO ANSWER
•  Crimes - human, animal poaching
•  EPC’s
•  Phylogenies
PCR AND FORENSICS
.
TESTING EVOLUTIONARY
QUESTIONS
COLOUR
INTENSITY
• From common ancestor or independent
acquisition? AMBIENT LIGHT
BARCODING
A powerful tool for studying biodiversity?
REMEMBER THIS?
Cytochrome oxidase C
Sequence of DNA code is ca. 700 units
HOW MANY SPECIES?
This “species” of skipper turns out to be 10
http://www.ornl.gov/TechResources/Human_Genome/home.html
Begun in 1990, ... U.S. Department of Energy and the National
Institutes of Health... Project goals are to identify all the 100,000
genes in human DNA, determine the sequences of the 3 billion
chemical base pairs that make up human DNA, An important feature of this project is the federal government's longstanding dedication to the transfer of technology to the private
sector...fostering the development of new medical applications. SEQUENCING BOTH THE
MOSQUITO AND PLASMODIUM
(MALARIA) GENOME
PROBLEMS WITH BIOTECH.
•  Diagnostics
•  What is a bad trait?
BIOINFORMATICS
•  The creation and of databases, algorithms,
computational and statistical techniques and
theory to solve formal and practical
problems arising from the management and
analysis of biological data
STEM CELLS
•  Cells with the ability to divide for indefinite
periods in culture and to give rise to
specialized cells.
CHARACTERISTICS OF
STEM CELLS
•  Cells capable of renewing themselves
through cell division, sometimes after long
periods of inactivity. •  They are unspecialized
•  They can be induced to become tissue- or
organ-specific cells with special functions.
COMPARE WITH OTHER
CELLS
•  Muscle cells, blood cells and nerve cells do
NOT normally replicate themselves
EXAMPLES
•  In human embryo blastocyst, inner cells
give rise to heart, lung, skin tissues, etc.
•  In some adult tissues (e.g. bone marrow)
adult stem cells generate replacement cells
for those lost through normal wear and tear
CELL DIFFERENTIATION
•  (Somatic) Adult stem cells normally
generate cells of the type of tissue on which
they reside – e.g. blood forming stem cell
•  Embryonic stem cells are pluripotent –
capable of differentiating into many types of
cells
CELL DIFFERENTIATION
•  (Somatic) Adult stem cells normally
generate cells of the type of tissue on which
they reside – e.g. blood forming stem cell
CELL DIFFERENTIATION
•  Embryonic stem cells - In human embryo
blastocyst, inner cells give rise to heart,
lung, skin tissues, etc DIRECTED
DIFFERENTIATION
Pancreas or nerve cells?
FUTURE TREATMENTS
Brain injuries
Spinal chord injuries
Heart damage
Missing teeth
Deafness
Diabetes