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Could you please insert ‘Genes and Diseases’ intro slide here?

Could you please insert ‘Genes and Diseases’ intro slide here?. What is DNA Day?. On April 25, 1953 Drs. James Watson and Francis Crick determined the structure of DNA. In April 2003 , Human Genome Project determined the entire DNA sequence of a human (3 billion letters).

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Could you please insert ‘Genes and Diseases’ intro slide here?

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  1. Could you please insert ‘Genes and Diseases’ intro slide here?

  2. What is DNA Day? On April 25, 1953 Drs. James Watson and Francis Crick determined the structure of DNA In April 2003, Human Genome Project determined the entire DNA sequence of a human (3 billion letters)

  3. Genes contain instructions to make proteins Information is stored in DNA RNA copy • Proteins do most of the work in a cell and provide much of its structure. Protein

  4. A change in gene result in a change in protein Thr Pro Glu Glu Lys Leu Thr Pro Glu Glu Lys Met Change in DNA is called a mutation SAM AND TOM ATE THE HAM ACT|CCT|GAG|GAG|AAG|CTG Possible Change: SAM AND TOM ATE THE HIM ACT|CCT|GAG|GAG|AAG|CGG Result: Changed meaning or function Variations in the DNA of different individuals can cause phenotypic changes in individuals

  5. Variations in the DNA of different individuals can cause visible changes in individuals • Just by looking around the room, we can see many examples of genetic variation. • Some genetic traits, such as skin color and eye color, are controlled by multiple genes • Others are controlled by only one gene • We are going to look at 7 traits that are each determined by one gene with two possible alleles.

  6. Single-gene Traits Tongue roll tt can’t roll tongue into “U” shape (homozygous recessive) T can roll tongue into “U” shape (heterozygous or homozygous dominant ) Laugh dimples • ll no dimples (homozygous recessive) • L dimples (heterozygous or homozygous dominant)

  7. Single-gene Traits Pinkies pp pinkies are straight when pressed side by side (homozygous recessive) P pinkies bend away from each other, toward the ring fingers, when pressed side by side (heterozygous or homozygous dominant) Crossing Thumbs • cc right thumb on top of clasped hands (homozygous recessive) • C left thumb on top of clasped hands (heterozygous or homozygous dominant )

  8. Single-geneTraits Widow’s peak ww no widow’s peak (homozygous recessive) W has a widow’s peak (heterozygous or homozygous dominant) Ear lobes • ee attached ear lobe (homozygous recessive) • E free ear lobe (heterozygous or homozygous dominant)

  9. Single-gene Traits Bending thumbs (Hitch-hiker’s thumb) • bb thumb bends at 90 degree angle (homozygous recessive) • B thumb is straight (heterozygous or homozygous dominant)

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  12. Genetic Wheel Results • There are 128 possible combinations from the 7 traits illustrated on the genetic wheel. • Are you the same as anyone else? • If this much genetic variation exists in traits that are visible, imagine how different we all are in ways that we can’t see!

  13. Variations in the DNA of different individuals can cause varying traits in individuals

  14. These traits can be inherited!

  15. Traits are inherited through genes Genes are on chromosomes One chromosome inherited from each parent We have two copies of each gene http://www.biotechnologyonline.gov.au

  16. Different versions of genes are alleles For each gene, you might have… Combinations of alleles determine what traits you have OR 2 different alleles 2 of same allele

  17. Can you roll your tongue? Yes! You carry a copy of the dominant allele. No! You have two copies of the recessive allele. If you inherit both alleles, the dominant one is expressed. or Dominant does NOT mean more common!

  18. Inheriting Traits- Tongue Rolling R = Roll allele (Dominant) Mother’s alleles r R Disease alleles can be inherited just like a “tongue rolling” allele... r = No-roll allele (Recessive) r r R r r Father’s alleles Each parent contributes 1 allele to offspring r r R r r 19

  19. Some diseases are caused by genetic factors and can be inherited A good example of genetically inherited disease is Cystic Fibrosis

  20. Thick mucus in airways and lungs Chronic Lung infections can cause permanent lung-cell damage. Digestive problems Lack of nutrient absorption Symptoms of Cystic Fibrosis

  21. What is the cause of Cystic Fibrosis?

  22. The lungs are lined with specialized cells. Cilia Out to mouth Dust Dirt Dust Mucus gland Mucus gland Dust Mucus

  23. These special cells clear mucus Cilia Mucous

  24. Cystic Fibrosis patients’ airways are dehydrated and cannot clear mucus. Healthy Airway CF Airway Normal mucus Thick, dry mucus

  25. As a result, CF airways accumulate bacteria and inflammatory cells. • Too many inflammatory cells can cause permanent lung-cell damage. Pseudomonas aeruginosa

  26. CFTR protein hydrates and allows mucus clearance =

  27. The CFTR in Lung Cells Cilia CFTR protein Cell nuclei

  28. Cystic Fibrosis Transmembrane Regulator (CFTR) Chromosome7 DNA DNA transcription RNA RNA translation CFTR protein Protein

  29. Mutations in the CFTR gene blocks CFTR protein function Healthy cell CFTR Cystic fibrosis cell Changes in the DNA sequence lead to a protein that cannot reach the plasma membrane. Mutant CFTR

  30. Cystic Fibrosis Activity You be the investigator… Find a cystic fibrosis patient

  31. Do not open the tubes!! • Analyze the contents of each tube for: • Mucus consistency • Presence of inflammatory cells • Evidence of infection with Pseudomonas aeruginosa (bacterial cells) Investigate the BALF A Record your findings on the worksheet provided. = inflammatory cell (macrophage) = bacterium (Pseudomonas)

  32. Who do think has Cystic Fibrosis? What would you do next to confirm the diagnosis?

  33. There are ~900 different mutations that have been found in the cftr gene. • To save time, we have printed the DNA sequences from the sequencing reactions for you. Sequence the DNA and look for mutations in the cftr gene. Remember the Central Dogma? DNARNAProtein

  34. How do mutations in the DNA sequence lead to defective proteins? DNARNAProtein AGG TCG GGT CAA CAA TGC DNA UCC AGC CCA GUU GUU ACG RNA *Convert the DNA sequence into the RNA intermediate. DNA A T C G RNA U A G C

  35. Now convert the mRNA message to a protein. DNARNAProtein UCC AGC CCA GUU GUU ACG mRNA Ser Ser Pro Val Val Thr Protein

  36. Which patient has the defective CFTR protein? Now you know that mutations in the genes (or DNA) can lead to changes in the protein.

  37. Genes & environment can work together to cause disease gene gene gene gene Will you have the disease? Disease gene yes “family history” Disease Cancer maybe environment smoking environment bad diet environment lack of exercise What diseases have both a genetic and an environmental component?

  38. mutation Cancer • Your own cells dividing out of control • tumor cells behave abnormally, invade tissues • Why? mutations in DNA tumor many mutations

  39. What causes these mutations? Environment (carcinogens) Can inherit mutations in certain genes

  40. How does knowing the genetics of diseases help us? Better understanding of disease can lead to better or safer treatments: Better, more specific drugs Gene replacement therapy Personalized medicine Does this mean we can cure everything? No

  41. END OF PRESENTAION FEEL FREE TO DISCUSS YOUR RESEARCH AND CAREERS

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