Ethics of Genetic Engineering

Technological Advance Could We? Should We?

National DNA registry

Prenatal phenotype diagnosis

Prenatal disorder correction

Non-medical enhancement

Transgenic crops

Transgenic humans

Rate from 1 (no) to 5 (yes) for these potential advances

Describe one pro and one con for each advance.

TransgenicOrganisms

Difficulties with DNA

1.There are often thousands of genes on a DNA molecule

• Electrophoresis

2.One cell normally provides too little material for study

• Polymerase Chain Reaction (PCR)• Gene cloning

Restriction Enzymes

• Bacterial defense against viral DNA• Excise DNA at specific sequences

CCTTTG AATTCCCAGAATCGGAAACTTAA GGGTCTTAG AATTCGGCCATATACG GCCGGTATATGCTTAA

Desired Gene

Target Sitesfor EcoRI

Electrophoresis• Separation of molecules based on size• Negatively charged DNA molecules are

pulled through a gel by an electrical field• Smaller molecules travel faster and farther

Restriction Fragment Length Polymorphisms (RFLP’s)

AAGAATTCCCTGATCCATATATATATATCGGATCTAGAATTC

TTCTTAAGGGACTAGGTATATATATATAGCCTAGATCTTAAC

AAGAATTCCCTGATCCATATATCGGATCTAGAATTCTTCTTAAGGGACTAGGTATATAGCCTAGATCTTAACVariations in DNA

Variations in fragment sizes

Variations in electrophoresis bands

Cujo

Jordan

Poop

Restriction Mapping

10 8 6 4 2 (kilobases)

Uncut plasmid

Cut with EcoRI

Cut with BamH3

Cut with Both

DNA Marker

Gene Cloning

Using Radioactive Probes

Each well contains a sample

An impression is made

Radioactive probes applied

Probe is complementary to desired gene

Adhered probe leaves dot on radiosensitive film

Intron Elimination

Intron

Complementary DNA (cDNA)

Eukaryotic mRNA

Polymerase Chain Reaction• In vitro amplification of a select length of DNA

DenaturationPrimingElongation Desired Gene

Organismal Cloning

StemCells