Transcript Genetic Alterations

Genetic Alterations
Albinism
Albinism

Robin

Peacock
Albinism

Squirrel

Coyote
Albinism

Elephant

African Mangaby
Albinism - Snowflake

Only albino gorilla know to science
and died of skin cancer.
Far Sighted
Hypertrichosis

A hair growing
disorder.
Lack of Clavicle
Lobster Claw Foot
Thalidamide Baby

Caused from a Birth Control Pill in
England.
Tri D Baby
Turner Syndrome

When females have only a single x
chromosome instead of two.

It is non lethal.
Human Tail
Genetic
Engineering
Genetic Engineering
 The
ability to move genetic
material (genes) from one
organism to another
Genetic Engineering

History
1000’s years people have changed
the characteristics of plants and
animals
 selective breeding
 exploitation of mutations
 dreamed of being able to artificially
create mutations

What is Genetic Engineering?


Involves the manipulation of genes
(DNA sequence) within a cell or
organism to produce a desired result.
a change in the genetic makeup of an
organism through:




deliberate addition (insertion)
Removal (deletion)
intentional mutation of DNA
Most commonly it involves the transfer of a
gene from one organism to another.
Examples
Bacteria produce Human insulin
needed for diabetics
 Transgenic pigs produce human
Factor VIII, a blood-clotting agent
needed by hemophiliacs
 Bacteria produce hormone BST which
helps control the production of milk.

Steps in Genetic Engineering
1)
2)
3)
Isolate the gene and cut it using
restriction enzymes
Cut bacterial DNA using restriction
enzymes
Splice the gene into bacterial DNA
by attaching “sticky” ends
Steps in Genetic Engineering
4)
5)
Place the engineered bacterial DNA
into a bacteria cell
Clone the bacteria and collect the
product
What Genetic
Engineering
Can Do
Agriculture






1. Plants resistant to virus, salt, drought
2. Plants resistant to frost and heat
3. Plants resistant to insects
4. Plants resistant to roundup
5. Animals that produce desired chemicals
in their products (TPA in milk)
6. Enhanced meat and milk production
Medicine
1. Production of pharmaceuticals
(insulin, TPA, interferon)
 2. Study of human cancer in mice
 3. Map the human genome
 4. Correct genetically caused
diseases

Clean up the environment
1. Bacteria to feed on oil slicks and
toxic chemicals
 2. Convert waste materials into
useful products (cellulose into plastic)
 3. Improve efficiency of industrial
processes

Using Bacteria as Factories
1.
 2.
 3.
 4.
 5.

Human Insulin
Human Growth Hormone
BST
TPA -- clot dissolving formula
Vaccines
Bovine somatotropin
BST
A hormone composed of protein that
that is produced by the cows pituitary
gland
 Helps control the production of milk
by assisting the regulation of
nutrients into the production of milk
or fat

BST
Supplementary BST causes the cow
to produce less fat and more milk
 By splicing genetic material into E.
coli bacteria the hormone can be
produced at relatively low cost

Genetic Alterations
Genetic engineering doesn’t have to
be completed in a lab.
 Some other ways to genetically alter
genes are:


Controlled Breeding
 Changing
the hereditary characteristics of
offspring by selecting parents
Inbreeding
Breeding of phenotypically similar
individuals
 May eventually produce weaker
organisms
 Increases the chances of harmful
homozygous recessive traits

Hybridization
Cross breeding two different but
related individuals
 Hybrid vigor – individual outproduces its parents
 Decreases the chances of harmful
homozygous recessive traits

Artificial Insemination

Placing sperm into the female
reproductive tract by means other
than natural mating.
Embryo Transfer

The transfer of fertilized egg(s) from
a donor female to one or more
recipient females
Cloning

The production of an exact genetic
copy of an organism
Mistakes

Sometimes, chromosomes break,
leading to 4 types of changes in
chromosome structure:
 Deletion
 Duplication
 Translocation
 Inversions
Cell Changes
Mutation – A change in the DNA
 Affects the production of proteins and
gives a new phenotype

Cell Changes
Chromosome Mutations – change the
structure of the chromosome
 Occur during cell division

Cell Changes

Deletion

A portion of one chromosome is lost
during cell division. That chromosome is
now missing certain genes. When this
chromosome is passed on to offspring
the result is usually lethal due to missing
genes.
Cri du chat
Wolf-Hirschhorn
Syndrome
Cell Changes
 Duplication
 If
the fragment joins the
homologous chromosome, then that
region is repeated
Fragile X
Cell Changes

Inversion – piece of chromosome
breaks and reattaches itself in
reverse
Cell Changes

Translocation




Broken piece attaches to a different
chromosome
A fragment of a chromosome is moved ("translocated") from one chromosome to another joins a non-homologous chromosome.
The balance of genes is still normal (nothing
has been gained or lost) but can alter
phenotype as it places genes in a new
environment.
Can also cause difficulties in egg or sperm
development and normal development of a
zygote.
"Philadelphia chromosome"
Translocation 9:22
Acute Myelogenous Leukemia
Cell Changes

Non-Disjunction


Chromosome pair fails to separate during
meiosis
Trisomy




Monosomy


Downs
Edwards
Patau
Turners
Polyploidy

Plants
Downs Syndrome
Boy

47,XY,+21
Gene Changes
Gene Mutations – involve a single
nitrogen base within a codon
 Point Mutation – substitution,
deletion, or addition of a base
 Frame-Shift Mutation – the addition
or deletion of a base
 Causes the gene to be read out of
order

Gene Changes
Mutagens – environmental factors
that damage DNA
 Examples –
 Cigarette Tars
 Radiation
 Asbestos
 UV Light

Chromosome Changes
Chromosome Map – diagram of where
genes are on a particular
chromosome
 Crossing Over – parts of genes
become rearranged during meiosis
 The closer genes are on a
chromosome, the less likely crossing
over will occur

Chromosome Changes
Electrophoresis – separation of
segments of DNA by electricity based
on their size
 Enzymes cut DNA at a specific base
sequence
 The shorter the pieces, the further
they travel in the gel

Gel Electrophoresis
Chromosome Changes
DNA Fingerprinting – the use of
electrophoresis to determine matches
in DNA
 Why map chromosomes?

Human Genetics

More difficult to study than other
organisms because it takes 75 years
to produce 3 generations of humans
Population Sampling

Use a small number of individuals to
represent the entire population.
Twins

Use identical twins to distinguish
between environmental and
hereditary factors
Pedigree Studies
Use family history to determine how a
trait is inherited
 Carrier – heterozygous – does not
have the trait, but may pass it on to
offspring

Pedigree Symbols
 Male
 Female
 Affected
male
 Affected female
 Mating
Pedigree Symbols

Parents

Siblings

Known heterozygote for
recessive allele

Death
Pedigree Symbols
Identical twins
Fraternal twins
?
Unknown
phenotype
Male at risk
Female carrier of an
x-linked trait
Female at risk
Dominant Pedigrees
Ear Lobe Attachment

Unattached is dominate (F) to Attached (ff)
Ear Lobe Attachment
Ear Lobe Attachment
Example
1
3
2
4
1
5
6
2
7
4
3
1
1
2
2
3
4
8
5
6
Ear Lobe Attachment
Example
I
II
1
ff
ff
2
3
4
ff
5
6
ff
2
3
4
ff
2
2
ff
ff
1
8
ff
1
IV
7
ff
1
III
ff
3
4
5
6
Ear Lobe Attachment
Example

I
II
Unattached earlobes have one Dominant allele
F_
ff
ff
F_
ff
ff
F_
F_
1
2
3
4
5
6
7
8
F_
ff
ff
ff
2
3
4
1
III
F_
ff
IV
F_
ff
F_
F_
ff
F_
1
2
3
4
5
6
1
2
Ear Lobe Attachment
Example
Because the father is recessive the
children have to be heterozygous
I
II
F_
ff
ff
F_
ff
1
2
3
4
5
F_
ff
ff
F_
F_
7
8
ff
ff
ff
2
3
4
1
III
F_
ff
IV
Ff
ff
1
2
1
Ff
3
2
Ff
ff
Ff
4
5
6
Ear Lobe Attachment
Example
Because the children are recessive the
mother is heterozygous
I
II
F_
ff
ff
F_
ff
ff
F_
F_
1
2
3
4
5
6
7
8
F_
ff
ff
ff
2
3
4
1
III
Ff
ff
IV
Ff
ff
1
2
1
Ff
3
2
Ff
ff
Ff
4
5
6
Recessive Pedigrees
Hints: 1. Individual with the trait has two normal
parents
2. Two affected parents can not have an
unaffected child
Human Genetic Traits
Single Allele Traits:
 Dominant – Huntington Disease,
Dwarfism, Polydactyly (extra fingers
and toes)
 Recessive – Albinism, Cystic fibrosis

Human Genetic Traits

Polygenic Traits:
Skin
 Hair and Eye Color
 Foot Size
 Height
 Nose Length

Human Genetic Traits

Multiple-Allele Traits
ABO blood groups
 Rh Factor in Blood

Human Genetic Traits

Sex Linked Traits
Color-blindness
 Hemophilia
 Muscular Dystrophy

Human Genetic Traits

Sex-Influenced Traits:

Baldness
Human Genetic Traits

Nondisjunction:
Down Syndrome
 Kleinfelter Syndrome
 Turner Syndrome

Detecting Genetic Disorders

Karyotype


The grouping of the chromosomes based
on size and the position of the
centromere
Amniocentesis

The process of removing fluid and cells
from around the fetus and checking for
abnormalities
Classification of Chromosomes

Normal
Female
Karyotype

Normal
Male
Karyotype