Genetic Genetic Engineering Engineering the manipulation of living the manipulation of living organisms for human useorganisms for human use

Chapter 13Chapter 13

Breeding strategies Breeding strategies • Selective breedingSelective breeding: only certain : only certain

individuals with certain traits are individuals with certain traits are selected to reproduceselected to reproduce

• InbreedingInbreeding: crosses individuals with : crosses individuals with similar traitssimilar traits

• HybridizationHybridization: crosses individuals : crosses individuals with different traits; tend to be hardier with different traits; tend to be hardier and healthier and healthier

Manipulating DNAManipulating DNA• Genetic engineeringGenetic engineering: making changes in the : making changes in the

DNA code of an organismDNA code of an organism

• Restriction enzymesRestriction enzymes: cut the DNA at specific : cut the DNA at specific sites by recognizing certain DNA sequencessites by recognizing certain DNA sequences– produces more manageable pieces of DNA to separate produces more manageable pieces of DNA to separate

and analyzeand analyze

• Gel electrophoresisGel electrophoresis: separates DNA fragments : separates DNA fragments through a gel using electricity; creates a “DNA through a gel using electricity; creates a “DNA fingerprint”fingerprint”– Identifying criminals Identifying criminals – Paternity (who is the father of the baby?)Paternity (who is the father of the baby?)

Gel ElectrophoresisGel Electrophoresis

DNA fingerprintingDNA fingerprinting

• method of DNA analysis which identifies method of DNA analysis which identifies individuals by examining DNA fragmentsindividuals by examining DNA fragments

• StepsSteps– sample of DNA is cut using restriction enzymessample of DNA is cut using restriction enzymes– fragments are separated using electrophoresis fragments are separated using electrophoresis

to create a pattern of bands (negatively-charged to create a pattern of bands (negatively-charged DNA moves towards positive-end of apparatus)DNA moves towards positive-end of apparatus)

– Shortest segments travel the furthest (easier to Shortest segments travel the furthest (easier to move through gel)move through gel)

Using DNAUsing DNA

• Recombinant DNARecombinant DNA: the : the manipulation of specific genes in the manipulation of specific genes in the cells of living organisms causing cells of living organisms causing them to produce new or unusual them to produce new or unusual substancessubstances

• Polymerase Chain Reaction Polymerase Chain Reaction (PCR): (PCR): uses DNA polymerase to create uses DNA polymerase to create thousands of copies of a genethousands of copies of a gene

Application of Gen. Eng.Application of Gen. Eng.

• TransgenicTransgenic Organisms Organisms– Contain DNA from another Contain DNA from another

speciesspecies– Example: insulin-producing Example: insulin-producing

bacteriabacteria– 52% of soybeans, 25% of corn 52% of soybeans, 25% of corn

are genetically-modified are genetically-modified (“GMO”)(“GMO”)

Application of Gen. Eng.Application of Gen. Eng.• Cloning Cloning

– Clone: member of a Clone: member of a population of population of genetically identical genetically identical cells that are produced cells that are produced from a single cellfrom a single cell

– Somatic Cell Nuclear Somatic Cell Nuclear TransferTransfer

• In 1997, Ian Wilmut In 1997, Ian Wilmut presented “Dolly”, the presented “Dolly”, the first cloned sheepfirst cloned sheep

• http://learn.genetics.utah.edu/content/tech/cloning/whatiscloning/

Steps of CloningSteps of Cloning

Human Genome ProjectHuman Genome Project

• An ongoing effort to analyze the An ongoing effort to analyze the human DNA sequencehuman DNA sequence

• Started in 1990, completed in 2000Started in 1990, completed in 2000

• Different scientists studied random Different scientists studied random fragments of DNA then combined fragments of DNA then combined their datatheir data

• Humans have approximately 35,000 Humans have approximately 35,000 genesgenes