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DNA Technology

DNA Technology. DNA Extraction. Chemical treatments cause cells and nuclei to burst The DNA is inherently sticky , and can be pulled out of the mixture This is called “spooling” DNA. “Spooled” DNA. Genetic Engineering. Manipulating a set of genetic changes on an

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DNA Technology

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  1. DNA Technology

  2. DNA Extraction • Chemical treatments cause cells and nuclei to burst • The DNA is inherently sticky, and can be pulled out of the mixture • This is called “spooling” DNA

  3. “Spooled” DNA

  4. Genetic Engineering • Manipulating a set of genetic changes on an organisms DNA Double Helix by Nancy Werlin

  5. Cutting DNA • Restriction enzymes -cut DNA at specific sequences • Enzymes recognize 4-6 nucleotides and cut both strands of DNA ex: EcoR1, Bam1 …. • Recombinant DNA– DNA from two sources combined to produce a single DNA molecule

  6. Restriction Enzymes • Useful to divide DNA into manageable fragments

  7. Electrophoresis • DNA sequences can be separated based on size and charge • The phosphate groups are negatively charged • DNA is placed in a gel and electricity is run through

  8. Electrophoresis • Negative DNA moves toward the positively charged end of gel plate • Smaller fragments move farther and faster

  9. Electrophoresis

  10. What would it mean if there were the same amount of nucleotides in each DNA fragment? • Where else have we seen different sizes of DNA displayed?

  11. Karyotypes 

  12. Steps in DNA Sequencing • Many copies of a single strand of DNA are placed in a test tube • DNA polymerase is added • A mixture of nucleotides is added some of which have been treated w/ radioactive phosphorous dye • Each base (A,T,C,G) has a different color dye

  13. Steps in DNA Sequencing • By chance, some dyed nucleotides & some untreated strands are added • Dye molecules are large and stop the chain from growing

  14. DNA Sequencing • The result is DNA fragments of multiple sizes with colors that can be identified A,G,C, T

  15. DNA Sequencing • After the gel separates the resulting fragments by size, we 'read' the sequence from bottom to top.

  16. Copying DNA • Polymerase Chain Reaction • Also called PCR • A method of making many copies of a piece of DNA

  17. Steps in Copying DNA • A DNA molecule is placed in a small test tube • DNA polymerasethat can work at high temps is added

  18. Steps in Copying DNA • The DNA is heatedto separate the two strands • Primers, short pieces of DNA complementary to the ends of the molecule to be copied, are added

  19. Copying DNA • The tube is cooled, and DNA polymerase adds new bases to the separated strands

  20. PCR Large amounts of DNA can be made from a small starting sample

  21. DNA Fingerprinting • Process that identifies an individuals DNA pattern for their genes, and “junk” repeats between genes. • Exons – code for proteins • Introns – spacers

  22. using specific restriction enzymes to cut DNA at points representing the targeted tandem repeat sequences. • FBI looks at 13 specific repeats to compare between people

  23. DNA Fingerprint

  24. Cloning • Clone- a member of a group of genetically identical cells grown from a single cell • May be produced by asexual reproduction (mitosis)

  25. Cloning organisms • A body cell from one organism and an egg cell from another are fused • The resulting cell divides like a normal embryo

  26. 2 types • Reproductive cloning- Dolly • Therapeutic cloning- Make tissues or organs that are genetically identical to the donor

  27. Cloning “Dolly”

  28. Ethics of Cloning • Should we clone organisms? • Should we use clones for “spare parts”?? • Will scientists try to design “perfect” people?? • Who should control the use and design of a humans??

  29. Human Genome Project

  30. Human Genome Project • Started in 1990 • Research effort to sequence all of our DNA (46 chromosomes) • Over 3.3 billion nucleotides • Mapping every gene location (loci) • Conducted by scientists around the world

  31. HGP Insights • Only 2% of human genome codes for proteins (exons) • Other 98% (introns) are non-coding • Only about 20,000 to 25,000 genes (expected 100,000) • Proteome – organism’s complete set of proteins • About 8 million single nucleotide polymorphisms (SNP) – places where humans differ by a single nucleotide • About ½ of genome comes from transposons (pieces of DNA that move to different locations on chromosomes)

  32. Benefits of Human Genome Project • Improvements in medical prevention of disease, gene therapies, diagnosis techniques … • Production of useful protein products for use in medicine, agriculture, bioremediation and pharmaceutical industries. • Improved bioinformatics – using computers to help in DNA sequencing …

  33. Benefits of Genetic Engineering

  34. Biotechnology - • The use of gene science to create new products from plants and animals

  35. BiotechnologyProvides: • Improved food products • Medical advances – • (gene therapy and genetic screening) • An enhanced environment

  36. Herbicide Resistant Crops • Soybeans: Roundup Ready • Corn: Roundup Ready, Liberty Link • Cotton: BXN, Roundup Ready • Canola: Liberty Link, Roundup Ready + CP4EPSPS = Roundup gene Ready

  37. Biotechnology Breakthroughs • Insulin (1982) • First commercial biotech product • Reliable, inexpensive source of insulin • Rice • Enriched with beta-carotene and iron • Bananas • Containing edible hepatitis vaccine

  38. Biotechnology Breakthroughs • Potatoes with higher solid content • Garlic that lowers cholesterol • Fruits and vegetables that reduce risks of cancer and heart disease

  39. Environmental Benefits • Reduced pesticide use • Lower energy requirements • Cleaner water • Less soil erosion

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