1. What is the lac operon? How is it controlled? QOD

2. Section 11-1 Control of Gene Expression

3. Gene Expression Only some genes are expressed at any given time Only some genes are expressed at any given time Cell specializationCell specialization Two steps: Two steps: Transcription – regulatory sitesTranscription – regulatory sites TranslationTranslation

4. The Lac Operon Jacob and Monod Jacob and Monod Studied gene expression in lac operon of E. Coli Studied gene expression in lac operon of E. Coli Structural genesStructural genes PromoterPromoter OperatorOperator OperonOperon

6. Controlling the Lac Operon Repression Repression Repressor proteinRepressor protein Regulator geneRegulator gene Activation Activation InducerInducer

7. Gene Expression in Eukaryotes Challenges: Challenges: Larger genomeLarger genome Several chromosomesSeveral chromosomes Specialized cellsSpecialized cells No operonsNo operons

8. How are genes controlled in eukaryotic organisms? QOD

9. Structure of Eukaryotic Genes Control before and after transcription Control before and after transcription DNA is coiled – affects gene expression DNA is coiled – affects gene expression EuchromatinEuchromatin HeterochromatinHeterochromatin Introns-Exons Introns-Exons Options for producing different proteinsOptions for producing different proteins Role for introns?Role for introns?

10. More on expression Control after transcription Control after transcription LocationsLocations Pre-mRNAPre-mRNA Splicing mRNA exons – Spliceosomes Splicing mRNA exons – Spliceosomes Alternative splicing Alternative splicing RNA as enzymes – ribozymes RNA as enzymes – ribozymes Enhancer control Enhancer control Enhancer regionEnhancer region Transcription factorsTranscription factors

11. Chapter 11 Removal of Introns After Transcription Section 1 Control of Gene Expression

12. Chapter 11 Controlling Transcription in Eukaryotes Section 1 Control of Gene Expression

13. How do complex multicellular organisms develop from an embryo? QOD

14. Section 11-2 Gene Expression and Development

15. Cell Differentiation Morphogenesis Morphogenesis Homeotic (Hox) genes Homeotic (Hox) genes Homeobox – 180 base pairsHomeobox – 180 base pairs Regulatory proteins – turn genes on/off Regulatory proteins – turn genes on/off Similar sequences found in many eukaryotic organisms Similar sequences found in many eukaryotic organisms

19. Cancer Tumor Tumor Benign tumorBenign tumor Malignant tumorMalignant tumor Types Types CarcinomasCarcinomas SarcomasSarcomas LymphomasLymphomas LeukemiaLeukemia

20. The Cell Cycle Normal – Cell needs: Normal – Cell needs: Adequate nutritionAdequate nutrition Attached to other cells, membrane, fibersAttached to other cells, membrane, fibers Stop dividing when become crowdedStop dividing when become crowded Cancer-causing Agents Cancer-causing Agents Growth factors and mutationsGrowth factors and mutations CarcinogensCarcinogens MutagensMutagens

21. More Causes More Causes Genetic factorsGenetic factors Environmental factorsEnvironmental factors Cigarette smoke Cigarette smoke Air and water pollution Air and water pollution UV radiation UV radiation Viral infection Viral infection Prevention Prevention Dietary methodsDietary methods Behavior modificationBehavior modification

22. More on Causes: Genes Oncogenes/Proto-oncogenes Oncogenes/Proto-oncogenes Tumor-suppressor genes Tumor-suppressor genes See Fig. 11-10, p. 214See Fig. 11-10, p. 214 Viruses Viruses

23. Chapter 11 Effect of Mutation on Gene Expression Section 2 Gene Expression in Development and Cell Division

24. Fig. 3.23

25. Stem Cells - Properties Undifferentiated (unspecialized) cells Undifferentiated (unspecialized) cells Differentiate to any type of cell based on signalsDifferentiate to any type of cell based on signals Depending on potency Depending on potency Self-renewing Self-renewing Mitosis  differentiated cell + another stem cellMitosis  differentiated cell + another stem cell

26. Potency of Stem Cells Totipotent Totipotent ZygoteZygote Pluripotent Pluripotent EmbryonicEmbryonic Multipotent Multipotent AdultAdult

27. Sources of stem cells Embryonic Embryonic From blastula stage of developing embryo (within first approx. 2 weeks)From blastula stage of developing embryo (within first approx. 2 weeks) PluripotentPluripotent Adult Adult Only in certain tissues (Brain, Bone marrow)Only in certain tissues (Brain, Bone marrow) MultipotentMultipotent Induced Pluripotent Stem Cells (IPS) Induced Pluripotent Stem Cells (IPS) Somatic cell  PluripotentSomatic cell  Pluripotent

28. Uses and Hurdles Potential Uses: Potential Uses: Cure diseasesCure diseases Repair spinal injuries/brain injuriesRepair spinal injuries/brain injuries Cloning organsCloning organs Hurdles: Hurdles: SignalsSignals Turning genes on/off is essential Turning genes on/off is essential CulturingCulturing Maintaining linesMaintaining lines Moral/Ethical debateMoral/Ethical debate