Genetics and BiotechnologyBiotechnologyFields Contributing to BiotechnologyApplications of BiotechnologySlide 5Genetics PrimerGenes are made of DNAGenes code for proteinsGene expression is regulatedProteins have many functionsProteins govern traitsVariation in traits is due to different allelesTransmitting genes to offspring“Breeding” vs. “Engineering”TermsSlide 16Insect resistance: Bt cornConcernsImpact of Bt corn on monarch butterfliesQuestions askedFindingsMore FindingsThe taco shell controversyRisks to natural plant populationsFarmer’s viewSlide 26Animal productionSlide 28Medical treatments: BiopharmaceuticalsUsing animals for pharmaceuticals: Molecular “pharming”Medical treatments: Gene therapySlide 32Environmental detoxification: PhytoremediationPhytodegradationPhytoaccumulationSlide 36Genetics and BiotechnologyBiotechnologyA group of many technologies that use living cells or their processes to make products or solve problemsUsed in basic and applied researchUsed in developing products for the marketplaceFields Contributing to BiotechnologyMedicinePlant ScienceFood ScienceGeneticsBiochemistryStatisticsMathematicsEngineeringComputer SciencePhilosophy (Ethics)Applications of BiotechnologyCloningGenesWhole organismsDrug productionInsulinDisease preventionHIV testBlood-type testPregnancy testApplications of BiotechnologyGenetic engineeringGene therapyGene discoveryHuman disease genesAlzheimer’s Breast cancer Huntington’s DiseasePlant genesCarotenoid synthesisOil productionGenetics PrimerGene: basic unit of heredityProtein: product of a geneGenotype: genetic makeup of an individual (sum of all the genes)Phenotype: observed traits of an individual, due to expression of its genes and interaction with the environmentGenes are made of DNACellNucleusSugar-phosphate backboneBasesDNA is a ladder-like double helix.Rungs of the ladder are made of pairs of four bases: A, C, G, TGenes code for proteinsThe sequence of bases in the DNA of a gene contains information to make a proteinThe DNA code is tripletEach triplet codes for an amino acid Example: the sequence TTG is the code for the amino acid tryptophanProteins are built from amino acidsTransferring the information from DNA to protein is called gene expressionproteingene (DNA)expressionGene expression is regulatedThe same set of genes is contained in (nearly) every cell of an organism, but...Not all genes are expressed in every cellGenes for helping plants absorb minerals from the soil are expressed in the rootGenes for plant oil production are expressed primarily in the embryoGenes for milk production in mammals are expressed in the mammary glandsProteins have many functionsTransport: hemoglobin carries oxygen in bloodStructural: collagen holds cells togetherReceptor: receives signals sent to cellRegulatory: control gene expressionEnzymes: catalyze chemical reactions in the cellProteins govern traitsAn organism’s appearance and qualities are the products of gene expressionGenes Proteins Traitsexpression=Variation in traits is due to different allelesAllele 1Allele 2Different forms of a gene (called alleles) can lead to different phenotypes (expression of traits)Gene A Trait (Fruit Color)PurpleWhiteTransmitting genes to offspringTraditional mating or breedingFemale contributes half her genes through eggMale contributes half his genes through spermOffspring have half their genes from mom and half from dadGenetic engineeringDonor contributes one or a few genesOffspring have all their own genes plus one or a few genes“Breeding” vs. “Engineering”TRADITIONAL BREEDINGGENETIC ENGINEERINGDesired geneDonor Commercial variety New varietyDesired geneDesired gene(cross)Desired geneCommercial variety New variety(transfer)==(many genes transferred)(one gene transferred)TermsTransgenic organismOne in which a gene has been introduced or modified by genetic engineeringGenetically engineered organism (GEO)Same as transgenic organismGenetically modified organism (GMO)Erroneously assumed to be same as transgenic organismActually, organisms can be modified genetically by “breeding” or by “engineering”Applications of BiotechnologyAgricultural food productionImproved productionDisease resistance Herbicide toleranceInsect resistance Improved food qualityModified oilsDelayed fruit ripeningNutritional enhancementInsect resistance: Bt cornPlants contain a gene from the soil bacterium, Bacillus thuringensis Bacillus thuringensis strains contain genes for a series of proteins called Bt toxinsBt toxins:are toxic to certain insects, including European corn borerbreak down rapidly in the soilare not harmful to mammals or birdsConcernsEnvironmental concernsEffect of Bt corn on monarchsInvasion of natural plant populations by genetically engineered cropsFood safety concernsStarLink in taco shellsFarmer’s point of viewImpact of Bt corn on monarch butterfliesIn 1999, an article* was published stating that pollen from Bt corn plants could kill monarch butterfly larvaeAssertion: planting of Bt corn poses a risk to monarch butterfliesConcerns were raised and more research was done* Losey et al., 1999. Transgenic pollen harms monarch larvae. Nature 399:214.Questions askedAre the data reproducible?Does the lab represent the field?What controls should be included?What does monarch reproductive behavior say about the lab experiment?Is all Bt corn the same?How does Bt corn compare to impact of current insect control methods?What is the greatest documented threat to monarch survival?Is the monarch endangered?FindingsSome varieties of Bt corn produce pollen with toxic levels of Bt; these are being phased out of commercial production in favor of varieties do not produce Bt in the pollenIn most parts of the country where corn is grown, the time of monarch larvae feeding does not coincide with the time that corn pollen is sheddingMore FindingsPollen does not accumulate on the same leaves as monarchs lay their eggs, even when milkweed plants (preferred host) are found in corn fieldsThe greatest threat to monarchs is predation.Overall conclusion: Bt corn does not pose a significant risk to monarch
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