Biotechnology. Professor Andrea Garrison Biology 11 Illustrations 2010 Pearson Education, Inc., unless otherwise noted

Transcription

1 Biotechnology Professor Andrea Garrison Biology 11 Illustrations 2010 Pearson Education, Inc., unless otherwise noted

2 Biotechnology Any technical procedure used to isolate, analyze or manipulate genes Foreign genes into living organism Bacteria/animals make pharmaceuticals drugs Designer fish that glow Bacteria that eat oil spills Cloning DNA fingerprinting Biotechnology 2

3 Biotechnology First methods Breeding livestock for desirable traits More recently (1970s & 1980s) Inserting genes from one organism into another Recombinant DNA transgenic organism Initial research with bacteria Biotechnology 3

4 Recombinant DNA Insert human gene into bacterium Allow bacteria to multiply As bacteria multiplied, it cloned the inserted gene Every bacterium capable of expressing foreign gene Can purify large quantities of gene products» Human growth hormone» Human insulin (humulin) Can clone genes to remove and put into other organisms Biotechnology 4

5 Recombinant DNA Bacteria contain circular DNA & plasmids Plasmids can integrate into main loop of this bacterium or another bacterium Biotechnology 5

6 Recombinant DNA Takes advantage of ability of plasmid to integrate into DNA loop Biotechnology 6

7 Recombinant DNA Biotechnology 7

8 Recombinant DNA Biotechnology 8

9 Recombinant DNA Biotechnology 9

10 How to Cut and Paste DNA Biotechnology 10

11 Recombinant DNA Biotechnology 11

12 Recombinant DNA Biotechnology 12

13 Recombinant DNA Biotechnology 13

14 Recombinant DNA Biotechnology 14

15 Recombinant DNA Biotechnology 15

16 Modern Methods to Clone DNA DNA synthesizer When base sequence is known Use machine to build copies of the gene Biotechnology 16

17 Modern Methods to Clone DNA Polymerase Chain Reaction (PCR) When base sequence is unknown Use machine to make copies of gene sample Used to make copies for DNA fingerprinting (discussed in lab) Biotechnology 17

18 Uses for Recombinant DNA Transgenic pharm animals Produce pharmaceutical drugs in their milk Produce enzymes/hormones for patients High risk of birth defects in pharm animals Only ~ 1% of eggs result in healthy animals with desired gene Biotechnology 18

19 Uses for Recombinant DNA Place beneficial genes into crop plants Resistance to frost, fungal diseases, salt in soil Ability to convert nitrogen to nitrate Pesticides Tomatoes with tough skin for machine picking CONCERN: many consumers don t want to eat genetically modified food Europe requires labels US doesn t require labels Biotechnology 19

20 Uses for Recombinant DNA Gene therapy Put healthy cells into patients with damaged genes Bone marrow transplants Put healthy genes into cells of patients with genetic defects Use virus to insert genes SCID Cystic Fibrosis Cancer Biotechnology 20

21 Cloning Single cell has all necessary DNA Let that cell divide to give other genetically identical cells Single-celled organisms binary fission in prokaryotes Mitosis in single-celled eukaryotes Biotechnology 21

22 Cloning Multicellular organisms Cells specialize as they mature Turn off genes not necessary for specialized function of that tissue type Plant cells can dedifferentiate Grow plant from a small cutting Gives rise to all cell types Ex: carrot root cells can grow into entire plant stems, leaves, root Biotechnology 22

23 Cloning Multicellular organisms Animal cloning more difficult Biotechnology 23

24 Animal Cloning 1950s success with frog embryos 1997 success with mammalian embryos Dolly sheep produced through reproductive cloning Dolly was only success of 277 attempts Nuclear transplantation (Somatic Cell Nuclear Transplantation SCNT) Biotechnology 24

25 Nuclear Transplantation Biotechnology 25

26 Animal Cloning Dolly and her surrogate mom Dolly aged rapidly Euthanized as a teenager of lung disease found in elderly sheep Biotechnology 26

27 Why Clone an Animal? To obtain desirable traits in agricultural animals High milk production Lean meat Medical use Pigs lack antigen that causes transplant rejection in humans Biotechnology 27

28 Why Clone an Animal? I miss my pet Biotechnology 28

29 Why Clone an Animal? Repopulate endangered species Biotechnology 29

30 Why Not Clone an Animal? Cloned animals Most attempts are unsuccessful Successes are not as healthy as those arising from natural fertilization of an egg Lack genetic diversity Biotechnology 30

31 Stem Cells Lack specialization Have not yet turned genes off Have potential to become a variety of cell types Biotechnology 31

32 Potential Uses for Stem Cells Understanding development & differentiation in healthy cells Improve treatments for diseases/birth defects caused by abnormal development and differentiation Provide tissues for people with diseased organs while waiting for transplant Reverse damage so transplant not necessary Parkinson s Type I diabetes Heart disease Build organs for people waiting for transplant Burn victims Drug testing Biotechnology 32

33 Stem Cells As embryo develops, the cells become more differentiated and more genes are turned off Biotechnology 33

34 Stem Cells Zygote (fertilized egg) Totipotent Can express all genes Has ability to differentiate into any cell type of fetus or placenta Biotechnology 34

35 Stem Cells Blastocyst (few days old) inner cell mass Pleuripotent Can express all except those needed for placental cells Has ability to differentiate into any cell type of fetus Biotechnology 35

36 Stem Cells Gastrula (~ 2-3 weeks old) and later Multipotent Can express only certain genes Has ability to become a variety of closely related cell types In mature tissues, source of cell replacement throughout life Biotechnology 36

37 Embryonic Stem Cells Inner cell mass of blastula Pleuripotent Flexibility to develop a variety of cell lines (use growth stimulating proteins) Very controversial Allows life to begin Destroys that life Biotechnology 37

38 Adult Stem Cells Found in mature tissues Multipotent Less flexibility to develop a variety of cell lines No controversy Biotechnology 38

39 Example of adult stem cell Biotechnology 39

40 Embryonic vs. Adult Stem Cells Embryonic stem cells Easier to grow in culture More versatile for development of cell types Very controversial Allows life to begin Destroys that life Can use nuclear transfer to create embryo, but still ending its life Adult stem cells More difficult to grow in culture Less versatile for development of cell types No controversy Finding ways to reverse differentiation and make them pleuripotent Already in use to treat leukemia and heart disease Biotechnology 40

41 Awesome Website Biotechnology 41

42 Genomics Mapping the entire genome of an organism Cracking the Code video explained the race to complete Human Genome Project and why the information is so important Only ~20,000 genes in human genome Rest is non-coding DNA Some regulates genes Most has unknown (if any) function Basis to provide Test for disease Cause of disease Treatment of disease Biotechnology 42

43 Proteomics Systematic study of full set of proteins Humans have more proteins than genes One gene may be used to produce several proteins Different cells splice a gene s mrna differently while still in nucleus, so cells use different portions of gene s mrna for translation of protein Biotechnology 43

44 Proteomics Proteins are workforce of cell Study of when/where proteins are produced & their interactions give understanding of cell function Biotechnology 44

45 Controversy Almost every aspect of Biotechnology has some controversy We are messing with life!!! Drugs/hormones treat disease Can also be used to make short kids basketball players Ability to select certain genes allows us to select for our children s traits Moral issue Lack of diversity within the gene pool DNA profiling Insurance companies Employers Stem cells destroy embryo Cloning of pets? Humans? Etc., etc., etc. Biotechnology 45