Regents Biology Genetic Engineering Biotechnology

Regents Biology We have been manipulating DNA for generations!  Artificial breeding  creating new breeds of animals & new crop plants to improve our food

Regents Biology Animal breeding

Regents Biology Breeding food plants  “Descendants” of the wild mustard  the “Cabbage family”

Regents Biology Breeding food plants Evolution of modern corn (right) from ancestral teosinte (left).

Regents Biology A Brave New World

Regents Biology The code is universal  Since all living organisms…  use the same DNA  use the same code book  read their genes the same way

Regents Biology TACGCACATTTACGTACGCGGATGCCGCGACTATGATC ACATAGACATGCTGTCAGCTCTAGTAGACTAGCTGACT CGACTAGCATGATCGATCAGCTACATGCTAGCACACYC GTACATCGATCCTGACATCGACCTGCTCGTACATGCTA CTAGCTACTGACTCATGATCCAGATCACTGAAACCCTA GATCGGGTACCTATTACAGTACGATCATCCGATCAGAT CATGCTAGTACATCGATCGATACTGCTACTGATCTAGC TCAATCAAACTCTTTTTGCATCATGATACTAGACTAGC TGACTGATCATGACTCTGATCCCGTAGATCGGGTACCT ATTACAGTACGATCATCCGATCAGATCATGCTAGTACA TCGATCGATACTGCTACTGATCTAGCTCAATCAAACTC TTTTTGCATCATGATACTAGACTAGCTGACTGATCATG ACTCTGATCCCGTAGATCGGGTACCTATTACAGTACGA TCATCCGATCAGATCATGCTAGTACATCGATCGATACT human genome 3.2 billion bases

Regents Biology Can we mix genes from one creature to another? YES!

Regents Biology Mixing genes for medicine…  Allowing organisms to produce new proteins  bacteria producing human insulin  bacteria producing human growth hormone

Regents Biology How do we do mix genes?  Genetic engineering  find gene  cut DNA in both organisms  paste gene from one creature into other creature’s DNA  insert new chromosome into organism  organism copies new gene as if it were its own  organism reads gene as if it were its own  organism produces NEW protein: Remember: we all use the same genetic code!

Regents Biology Cutting DNA  DNA “scissors”  enzymes that cut DNA  restriction enzymes  used by bacteria to cut up DNA of attacking viruses  EcoRI, HindIII, BamHI  cut DNA at specific sites  enzymes look for specific base sequences GTAACGAATTCACGCTT CATTGCTTAAGTGCGAA GTAACG|AATTCACGCTT CATTGCTTAA|GTGCGAA

Regents Biology Restriction enzymes  Cut DNA at specific sites  leave “sticky ends” GTAACG AATTCACGCTT CATTGCTTAA GTGCGAA GTAACGAATTCACGCTT CATTGCTTAAGTGCGAA restriction enzyme cut site

Regents Biology Sticky ends  Cut other DNA with same enzymes  leave “sticky ends” on both  can glue DNA together at “sticky ends” GTAACG AATTCACGCTT CATTGCTTAA GTGCGAA gene you want GGACCTG AATTCCGGATA CCTGGACTTAA GGCCTAT chromosome want to add gene to GGACCTG AATTCACGCTT CCTGGACTTAA GTGCGAA combined DNA

Regents Biology Sticky ends help glue genes together TTGTAACGAATTCTACGAATGGTTACATCGCCGAATTCACGCTT AACATTGCTTAAGATGCTTACCAATGTAGCGGCTTAAGTGCGAA gene you wantcut sites AATGGTTACTTGTAACG AATTCTACGATCGCCGATTCAACGCTT TTACCAATGAACATTGCTTAA GATGCTAGCGGCTAAGTTGCGAA chromosome want to add gene tocut sites AATTCTACGAATGGTTACATCGCCG GATGCTTACCAATGTAGCGGCTTAA isolated gene sticky ends chromosome with new gene added TAACGAATTCTACGAATGGTTACATCGCCGAATTCTACGATC CATTGCTTAAGATGCTTACCAATGTAGCGGCTTAAGATGCTAGC sticky ends stick together DNA ligase joins the strands Recombinant DNA molecule

Regents Biology Why mix genes together? TAACGAATTCTACGAATGGTTACATCGCCGAATTCTACGATC CATTGCTTAAGATGCTTACCAATGTAGCGGCTTAAGATGCTAGC  Gene produces protein in different organism or different individual aa “new” protein from organism ex: human insulin from bacteria human insulin gene in bacteria bacteriahuman insulin How can bacteria read human DNA?

Regents Biology Uses of genetic engineering  Genetically modified organisms (GMO)  enabling plants to produce new proteins  Protect crops from insects: BT corn  corn produces a bacterial toxin that kills corn borer (caterpillar pest of corn)  Extend growing season: fishberries  strawberries with an anti-freezing gene from flounder  Improve quality of food: golden rice  rice producing vitamin A improves nutritional value

Regents Biology Bacteria  Bacteria are great!  one-celled organisms  reproduce by mitosis  easy to grow, fast to grow  generation every ~20 minutes

Regents Biology Bacterial DNA  Single circular chromosome  only one copy = haploid  no nucleus  Other DNA = plasmids! bacteria chromosome plasmids

Regents Biology There’s more…  Plasmids  small extra circles of DNA  carry extra genes that bacteria can use  can be swapped between bacteria  bacterial sex!!  rapid evolution = antibiotic resistance  can be picked up from environment

Regents Biology How can plasmids help us?  A way to get genes into bacteria easily  insert new gene into plasmid  insert plasmid into bacteria = vector  bacteria now expresses new gene  bacteria make new protein + transformed bacteria gene from other organism plasmid cut DNA recombinant plasmid vector glue DNA

Regents Biology Grow bacteria…make more grow bacteria harvest (purify) protein transformed bacteria plasmid gene from other organism + recombinant plasmid vector

Regents Biology Applications of biotechnology

Regents Biology I’m a very special pig! Got any Questions?

Regents Biology Biotechnology Gel Electrophoresis

Regents Biology Many uses of restriction enzymes…  Now that we can cut DNA with restriction enzymes…  we can cut up DNA from different people… or different organisms… and compare it  why?  forensics  medical diagnostics  paternity  evolutionary relationships  and more…

Regents Biology Comparing cut up DNA  How do we compare DNA fragments?  separate fragments by size  How do we separate DNA fragments?  run it through a gelatin  gel electrophoresis  How does a gel work?

Regents Biology Gel electrophoresis  A method of separating DNA in a gelatin-like material using an electrical field  DNA is negatively charged  when it’s in an electrical field it moves toward the positive side + – DNA        “swimming through Jello”

Regents Biology  DNA moves in an electrical field…  so how does that help you compare DNA fragments?  size of DNA fragment affects how far it travels  small pieces travel farther  large pieces travel slower & lag behind Gel electrophoresis + – DNA        “swimming through Jello”

Regents Biology Gel Electrophoresis longer fragments shorter fragments power source completed gel gel DNA & restriction enzyme wells - +

Regents Biology Running a gel 12 cut DNA with restriction enzymes fragments of DNA separate out based on size 3 Stain DNA  ethidium bromide binds to DNA  fluoresces under UV light

Regents Biology DNA fingerprint  Why is each person’s DNA pattern different?  sections of “junk” DNA  doesn’t code for proteins  made up of repeated patterns  CAT, GCC, and others  each person may have different number of repeats  many sites on our 23 chromosomes with different repeat patterns GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGAA GCTTGTAACGGCATCATCATCATCATCATCCGGCCTACGCTT CGAACATTGCCGTAGTAGTAGTAGTAGTAGGCCGGATGCGAA

Regents Biology Allele 1 GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGAA repeats DNA patterns for DNA fingerprints cut sites GCTTGTAACG GCCTCATCATCATCGCCG GCCTACGCTT CGAACATTGCCG GAGTAGTAGTAGCGGCCG GATGCGAA 123 DNA  –+ allele 1 Cut the DNA

Regents Biology Person 1 GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGAA Differences between people cut sites DNA  –+ person 1 Person 2: more repeats GCTTGTAACGGCCTCATCATCATCATCATCATCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAGTAGTAGTAGGCCGGATGCGAA DNA fingerprint person 2 123

Regents Biology Uses: Evolutionary relationships  Comparing DNA samples from different organisms to measure evolutionary relationships – + DNA  turtlesnakeratsquirrelfruitfly

Regents Biology Uses: Medical diagnostic  Comparing normal allele to disease allele chromosome with disease-causing allele 2 chromosome with normal allele 1 – + allele 1 allele 2 DNA  Example: test for Huntington’s disease

Regents Biology Uses: Forensics  Comparing DNA sample from crime scene with suspects & victim – + S1 DNA  S2S3V suspects crime scene sample

Regents Biology DNA fingerprints  Comparing blood samples on defendant’s clothing to determine if it belongs to victim  DNA fingerprinting

Regents Biology RFLP / electrophoresis use in forensics  1st case successfully using DNA evidence  1987 rape case convicting Tommie Lee Andrews “standard” semen sample from rapist blood sample from suspect How can you compare DNA from blood & from semen? RBC?

Regents Biology Electrophoresis use in forensics  Evidence from murder trial  Do you think suspect is guilty? “standard” blood sample 3 from crime scene “standard” blood sample 1 from crime scene blood sample 2 from crime scene blood sample from victim 2 blood sample from victim 1 blood sample from suspect OJ Simpson N Brown R Goldman

Regents Biology Uses: Paternity  Who’s the father? + DNA  childMomF1F2 –

Regents Biology I’m a-glow! Got any Questions?

Regents Biology Using Stem Cells  A stem cell is a cell that can continuously divide and differentiate into various tissues.  Some stem cells have more potential to differentiate than others.  Adults’ bodies have some multipotent cells that can be removed, frozen or cultured, and used for medical treatments.  The cells of new embryos have more potential uses.  The use of embryos for stem cell research poses ethical problems.  An alternative source of embryonic stem cells is through SCNT (somatic cell nuclear transplant).

Regents Biology What are Stem Cells? Stem Cells are extraordinary because: They can divide and make identical copies of themselves over and over again (Self-Renewal) Remain Unspecialized with no ‘specific’ function or become.... Specialized (Differentiated) w/ the potential to produce over 200 different types of cells in the body.

Regents Biology The Major Types of Stem Cells A.Embryonic Stem Cells From blastocysts left over from In-Vitro Fertilization in the laboratory From aborted fetuses B. Adult Stem Cells Stem cells have been found in the blood, bone marrow, liver, kidney, cornea, dental pulp, umbilical cord, brain, skin, muscle, salivary gland....

Regents Biology

Regents Biology Advantages and Disadvantages to Embryonic and Adult Stem Cells. Embryonic S.C.Adult S.C. “Pluripotent” (can become any cell) “Multipotent” (“can become many but not any”) Stable. Can undergo many cell divisions. Less Stable. Capacity for self-renewal is limited. Easy to obtain but blastocyst is destroyed. Difficult to isolate in adult tissue. Possibility of rejection??Host rejection minimized

Regents Biology Reprinted with permission of Do No Harm. Click on image for link to website.

Regents Biology  WBnL0zjU WBnL0zjU

Regents Biology Why is Stem Cell Research So Important to All of Us? Stem cells allow us to study how organisms grow and develop over time. Stem cells can replace diseased or damaged cells that can not heal or renew themselves. We can test different substances (drugs and chemicals) on stem cells. We can get a better understanding of our “genetic machinery.”

Regents Biology What Human Diseases are Currently Being Treated with Stem Cells?  Parkinson’s Disease  Leukemia (Bone Marrow Transplants)  Skin Grafts resulting from severe burns Stem Cell Therapy has the Potential to:  Regenerate tissues/organs  Cure diseases like diabetes, multiple sclerosis, etc.

Regents Biology Why the Controversy Over Stem cells?  Embryonic Stem cells are derived from extra blastocysts that would otherwise be discarded following IVF.  Extracting stem cells destroys the developing blastocyst (embryo). -Questions for Consideration- Is an embryo a person? Is it morally acceptable to use embryos for research? When do we become “human beings?”

Regents Biology Key Concept Questions  How are transgenic organisms useful to human beings?  Genetic engineering has spurred the growth of biotechnology, a new industry that is changing the way we interact with the living world  How are cloning and stem cell research related?  Cloning can produce organisms that are genetically identical to preexisting individuals. Stem cells can be used to grow new tissues.