Genetic AlterationsGenetic Alterations

AlbinismAlbinism

AlbinismAlbinism

Robin

Peacock

Squirrel

Coyote

AlbinismAlbinism

AlbinismAlbinism

Elephant

African Mangaby

Albinism - SnowflakeAlbinism - SnowflakeOnly albino gorilla know to science

and died of skin cancer.

Far SightedFar Sighted

HypertrichosisHypertrichosis

A hair growing disorder.

Lack of ClavicleLack of Clavicle

Lobster Claw FootLobster Claw Foot

Thalidamide BabyThalidamide Baby

Caused from a Birth Control Pill in England.

Tri D BabyTri D Baby

Turner SyndromeTurner Syndrome

When females have only a single x chromosome instead of two.

It is non lethal.

Human TailHuman Tail

Genetic Genetic EngineeringEngineering

Genetic EngineeringGenetic Engineering

The ability to move genetic material (genes) from one organism to another

Genetic EngineeringGenetic Engineering

History1000’s years people have changed

the characteristics of plants and animalsselective breedingexploitation of mutations

dreamed of being able to artificially create mutations

What is Genetic Engineering?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.

ExamplesExamples

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) Isolate the gene and cut it using restriction enzymes

2) Cut bacterial DNA using restriction enzymes

3) Splice the gene into bacterial DNA by attaching “sticky” ends

Steps in Genetic Engineering

4) Place the engineered bacterial DNA into a bacteria cell

5) 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 mice3. Map the human genome4. 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. Human Insulin2. Human Growth Hormone3. BST4. TPA -- clot dissolving formula5. 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 AlterationsGenetic 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 out-produces 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

MistakesMistakes

Sometimes, chromosomes break, leading to 4 types of changes in chromosome structure:DeletionDuplicationTranslocationInversions

Cell Changes

Mutation – A change in the DNAAffects 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

DeletionA 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 chatCri du chat

Wolf-Hirschhorn Wolf-Hirschhorn SyndromeSyndrome

Cell ChangesCell Changes

DuplicationIf the fragment joins the If the fragment joins the

homologous chromosome, then that homologous chromosome, then that region is region is repeatedrepeated

Fragile XFragile 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 ("trans-located") 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" "Philadelphia chromosome" Translocation 9:22 Translocation 9:22

Acute Acute MyelogenousMyelogenous Leukemia Leukemia

Cell Changes

Non-Disjunction Chromosome pair fails to separate during

meiosis Trisomy

Downs Edwards Patau

Monosomy Turners

Polyploidy Plants

Downs Syndrome Downs Syndrome BoyBoy

47,XY,+2147,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 RadiationAsbestosUV 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 ElectrophoresisGel 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 FemaleAffected maleAffected femaleMating

Pedigree Symbols

Parents

Siblings

Known heterozygote for recessive allele

Death

Pedigree Symbols

Fraternal twins Identical twins

Unknownphenotype

??

Female carrier of an x-linked trait

Male at risk

Female at risk

Dominant PedigreesDominant Pedigrees

Ear Lobe Attachment

Unattached is dominate (F) to Attached (ff)

Ear Lobe Attachment

Ear Lobe Attachment Example

1

1

1

1

2

2

2

2

3

3

4

4 5 6

3 4 5 6 7 8

Ear Lobe Attachment Example

I

II

III

IV

1

1

1

1

2

2

2

2

3

3

4

4 5 6

ff ff

ff

ff

ff

1 2

ff ff

ff3 4 5 6 7 8

ff ff

Ear Lobe Attachment Example

Unattached earlobes have one Dominant allele

I

II

III

IV

1

1

1

2

2

2

3

3

4

ff ff

ff

ff

ff

F_

ff

F_

F_F_F_

F_

F_

F_

1 2F_

ff ff

ff

F_

3 4 5 6 7 8

ff

21 4 5 6

Ear Lobe Attachment Example

Because the father is recessive the children have to be heterozygous

I

II

III

IV

1

1

1

1

2

2

2

2

3

3

4

4 5 6

ff ff

ff

ff

ff

F_

ff

F_

FfFfFf

F_

Ff

F_

1 2F_

ff ff

ff

F_

3 4 5

ff

7 8ff

Ear Lobe Attachment Example

Because the children are recessive the mother is heterozygous

F_I

II

III

IV

1

1

1

1

2

2

2

2

3

3

4

4 5 6

F_

ff ff

ff

ff ff

ff

ff

ff

F_F_

ff

F_

FfFfFf

Ff

Ff

ff

3 4 5 6 7 8

Recessive PedigreesRecessive 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:SkinHair and Eye ColorFoot SizeHeightNose Length

Human Genetic Traits

Multiple-Allele TraitsABO blood groupsRh Factor in Blood

Human Genetic Traits

Sex Linked TraitsColor-blindnessHemophiliaMuscular Dystrophy

Human Genetic Traits

Sex-Influenced Traits:Baldness

Human Genetic Traits

Nondisjunction:Down SyndromeKleinfelter SyndromeTurner 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 ChromosomesClassification of Chromosomes

NormalNormalFemale Female KaryotypeKaryotype

NormalNormalMale Male KaryotypeKaryotype