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 BiotechnologyBiotechnologyA group of many technologies that use living cells or their processes to make products or solve problemsUsed in basic and applied researchUsed in developing products for the marketplaceFields Contributing to BiotechnologyMedicinePlant ScienceFood ScienceGeneticsBiochemistryStatisticsMathematicsEngineeringComputer SciencePhilosophy (Ethics)Applications of BiotechnologyCloningGenesWhole organismsDrug productionInsulinDisease preventionHIV testBlood-type testPregnancy testApplications of BiotechnologyGenetic engineeringGene therapyGene discoveryHuman disease genesAlzheimer’s Breast cancer Huntington’s DiseasePlant genesCarotenoid synthesisOil productionGenetics PrimerGene: basic unit of heredityProtein: product of a geneGenotype: 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 backboneBasesDNA is a ladder-like double helix.Rungs of the ladder are made of pairs of four bases: A, C, G, TGenes code for proteinsThe sequence of bases in the DNA of a gene contains information to make a proteinThe DNA code is tripletEach triplet codes for an amino acid Example: the sequence TTG is the code for the amino acid tryptophanProteins are built from amino acidsTransferring the information from DNA to protein is called gene expressionproteingene (DNA)expressionGene expression is regulatedThe same set of genes is contained in (nearly) every cell of an organism, but...Not all genes are expressed in every cellGenes for helping plants absorb minerals from the soil are expressed in the rootGenes for plant oil production are expressed primarily in the embryoGenes for milk production in mammals are expressed in the mammary glandsProteins have many functionsTransport: hemoglobin carries oxygen in bloodStructural: collagen holds cells togetherReceptor: receives signals sent to cellRegulatory: control gene expressionEnzymes: 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 offspringTraditional mating or breedingFemale contributes half her genes through eggMale contributes half his genes through spermOffspring have half their genes from mom and half from dadGenetic engineeringDonor contributes one or a few genesOffspring 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)TermsTransgenic organismOne in which a gene has been introduced or modified by genetic engineeringGenetically engineered organism (GEO)Same as transgenic organismGenetically modified organism (GMO)Erroneously assumed to be same as transgenic organismActually, organisms can be modified genetically by “breeding” or by “engineering”Applications of BiotechnologyAgricultural food productionImproved productionDisease resistance Herbicide toleranceInsect resistance Improved food qualityModified oilsDelayed fruit ripeningNutritional enhancementInsect resistance: Bt cornPlants contain a gene from the soil bacterium, Bacillus thuringensis Bacillus thuringensis strains contain genes for a series of proteins called Bt toxinsBt toxins:are toxic to certain insects, including European corn borerbreak down rapidly in the soilare not harmful to mammals or birdsConcernsEnvironmental concernsEffect of Bt corn on monarchsInvasion of natural plant populations by genetically engineered cropsFood safety concernsStarLink in taco shellsFarmer’s point of viewImpact of Bt corn on monarch butterfliesIn 1999, an article* was published stating that pollen from Bt corn plants could kill monarch butterfly larvaeAssertion: planting of Bt corn poses a risk to monarch butterfliesConcerns were raised and more research was done* Losey et al., 1999. Transgenic pollen harms monarch larvae. Nature 399:214.Questions askedAre 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?FindingsSome 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 pollenIn 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 FindingsPollen does not accumulate on the same leaves as monarchs lay their eggs, even when milkweed plants (preferred host) are found in corn fieldsThe greatest threat to monarchs is predation.Overall conclusion: Bt corn does not pose a significant risk to monarch