PowerPoint Presentation

3.5 continued

Gene TransferTechnique of taking a gene out of one organism and placing it in another. Possible because the genetic code is universal.Examples:Genes from fish put into produce to resist freezingBt corn that resists pests

What is Bt?Bacillus thuringiensis (Bt) is a soil bacterium that produces insecticidal toxins. Genes from Bt can be inserted into crop plants to make them capable of producing an insecticidal toxin and therefore resistant to certain pests.If Bt crops kill insects, what happens to the local ecosystem that relies on the insects for food or pollination?

TOKIs it ethically acceptable to alter an organisms genetic identity?If the organism did not have that gene in the first place, could there be a good reason for its absence?Why are people so worried about this new technology? In selective breeding, thousands of genes are mixed and matched. With GMOs, only one is changed. Is that not less risky?Would strict vegetarians be able to eat a fruit with a fish gene in it?

CloningRestriction enzymes (endonucleases) recognize a sequence of 4-6 bases and cut the DNA at that point.The gene can then be removed.DNA ligase is used to paste the genes into another organisms genome.

The gene must be inserted into a plasmid from a host cellHost DNA is cut using REs The gene to be copied is insertedLigase seals it togetherThe plasmid is now called a recombinant plasmid and can be used as a vector, which is a tool for introducing a new gene into an organisms genetic makeup.

Plasmid is put into host bacteriumBacterium reproduces, copying the geneThe gene is expressed and the protein that the gene codes for is synthesized.

Transgenic PlantsUndesirable gene can be removed gene no longer expressedDesirable gene inserted new trait expressedCorn that kills pest speciesGolden riceSoy with higher levels of oleic acidRoundup resistant alfalfa

Transgenic animalsCan be used for medical treatmentsDairy animals are commonly usedHigh milk outputShort generation timesGene inserted into the animals genome Protein produced in the animals milkProtein the isolated from the milk and used in medical treatmentExample: used to treat antithrombin deficiency (clotting disorder)

Natural CloningSome plants and animals are capable of cloning themselvesPros- no need for fertilization, all desirable characteristics passed on to offspringCon- all weaknesses passed on to offspringExample: some types of sharks have undergone parthenogenesis in captivity

Reproductive CloningMakes a whole individualUndifferentiated cells can be removed from a developing embryo; will result in identical organismsSomatic cell nuclear transferSomatic cell is collected and the nucleus is removedUnfertilized egg is collected and the nucleus is removedElectrical current is used to fuse the egg and nucleus from the somatic cellCell develops in vitro Embryo placed into womb

Therapeutic CloningAKA stem cell researchDoes not make whole individuals, but embryos for stem cells insteadUndifferentiated cells are culturedThese cells can then be made into any type of cells/tissues for medical treatment

TOKSome people think that both methods of cloning are unacceptable, others think both are fine, and some are in between. What is your stance?