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Thanks to: Washington U, Harvard-MIT Broad Inst., DARPA-BioSpice, DOE-GTL, EU-MolTools, NGHRI-CEGS, NHLBI-PGA, NIGMS-SysBio, PhRMA, Lipper Foundation Agencourt, Ambergen, Atactic, BeyondGenomics, Caliper, Genomatica, Genovoxx, Helicos, MJR, NEN, Nimblegen, SynBioCorp, ThermoFinnigan, Xeotron/Invitrogen For more info see: arep.med.harvard.edu iGEM Harvard Mon 6-Jun-2005 9:30-11:00 AM ELSI: Risks and Rewards of Synthetic Biology
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Harvard iGEM Tag! / BioWire (Signal Transfer)Tag! / BioWire (Signal Transfer) Paula, Patrick, Jenny, Kang-Xing Thermal / Diagnostic DetectionThermal / Diagnostic Detection Chris, Ives, Thomas, Danny, Connie Cell Density DetectionCell Density Detection Yin, Hing, Orr, Sasha June 2 10:00-10:45 (George, Biolabs Main Lecture Hall) Overview of synthetic biology -- Slides [1] [1] June 6 9:30-11:00 (George) Risks and Rewards -- Slides[2] [2]
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Why IGEM competition should not be like Core-War'84, Robot Wars'94, etc. Computer Viruses and Hacking Take $1.6 Trillion Toll on Worldwide Economy http://seclists.org/lists/isn/2000/Jul/0070.html http://seclists.org/lists/isn/2000/Jul/0070.html
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3 Exponential technologies (synergistic) Shendure J, Mitra R, Varma C, Church GM, 2004 Nature Reviews of Genetics. Carlson 2003 ; Kurzweil 2002; Moore 1965 urea E.coli B12 tRNA operons telegraph Computation & Communication (bits/sec) Synthesis (daltons) Analysis (bp/$) tRNA
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It seemed like a good idea at the time. Crops River life Grain trade Livestock Fertilizer Nuclear Power Tankers Pets Malaria Cholera Yersinia Flu & HIV Anoxic fish TMI, Chernobyl Mussels & sea snakes Australian herbicide
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Responsible Conduct In Research http://www.nap.edu/readingroom/books/obas/ "If scientists find that their discoveries have implications for some important aspect of public affairs, they have a responsibility to call attention to the public issues involved.. A good example is the response of biologists to the development of recombinant DNA technologies -- first calling for a temporary moratorium on the research and then helping to set up a regulatory mechanism to ensure its safety." http://www.aaes.org/membership/index.asp
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Synthetic Biology Policy Closed vs open -- International transparency Lower costs & availability impact on biohackers Rapid response tools Culture of cooperation Professional society with code of ethics Licensing & monitoring vendors, signatures/IDs NHGRI ELSI 1990-present Synthetic Biology 1.0 June 2004 Sloan Foundation Study Science & Technology Expert Partnership Jun'05 Center for Strategic and International Studies (CSIS) Carnegie Foundation The J. Craig Venter Institute National Science Advisory Board for Biosecurity (NSABB) Jul'05
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1977 1995 cult Aum Shinrikyo, aerosolize anthrax & botulinum in Tokyo on 8 occasions.
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Bio-risks, Biosecurity Accidental Bio-Risks IL4-pox Purposeful Bio-Risks "the most powerful..called Anthrax 836 isolated ironically after another accident..disinfected the sewer but..one of the rodents captured in the Kirov sewers had developed a new strain, more virulent than the original. The army immediately ordered him to cultivate the new strains." --Ken Alibek in "Biohazard" Uncertain Bio-Risks Gene therapy, GMOs, Ecology
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Accidental Bio-risk in research "Recently immunized genetically resistant mice with the virus expressing IL-4 also resulted in significant mortality due to fulminant mousepox." Jackson et al. (2001) J Virol. 75:1205-10. A smallpox victim in Gloucester, 1923
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Uncertain Bio-risks Gene therapy: Immune reactions (Penn) Insertions in tumor suppressor genes & onocogenes Genetically modified organisms (GMO) uncontrolled spread of: Ice-nucleation & ice resistance (AGS) Herbicide resistance (Monsanto) Allergens Pharmaceuticals & vaccines Drought resistance Eco-engineering Ocean fertilization
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ELSI: Safe Synthetic Biology Church, G.M. (2004) A synthetic biohazard non-proliferation proposal. http://arep.med.harvard.edu /SBPhttp://arep.med.harvard.edu /SBP Monitor oligo synthesis via expansion of Controlled substances, Select Agents, Recombinant DNA Computational tools are available; small number of reagent, instrument & synthetic DNA suppliers at present. System modeling checks for synthetic biology projects Multi-auxotrophy & novel genetic codes prevent functional transfer of DNA to other cells.
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Encourage responsibility in the entire bio-supply-chain via licensing 1. Chemicals: Phosphoramidites 2. Instruments 3. Synthetic oligonucleotides 4. Synthetic genes/genomes 5. Design & ordering software (check for select agents) 6. Educational goals (defense not offense) 7. Intellectual property & know-how 8. Engineering standards & societies 9. Network of trainees (no trainee left behind)
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Defense not offense (albeit a perfect defense can allow first strikes) How would you make cells resistant to all viruses (phages)? Auto-destruct at a specific conditions (temperature) Toxin-antitoxin pairs: RelB/E, MazE/, yeeU/V, CcdB inhibits GyrA Auxotrophs (metabolic dependencies) Inexpensive monitoring & diagnostics, bio-weather-map Optimal biosynthesis e.g. artemesinin (malaria) Explore epitopes & vaccines
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Safety via blocking exchange Can we make a cell which is resistant to all viruses and incapable of *functional* DNA exchange in or out? Options: Restriction enzymes (mainly incoming) Chirality (very challenging) Genetic code remapping Micrococcus luteus is naturally missing 6 codons: UUA(L), CUA(L), AUA(I), GUA(V), CAA(Q), AGA(R). Kowal, AK, & Oliver, JS NAR 1997, 25: 4685
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108 TypeIIS Endonucleases FokI GGATG (N9/13) 5 +4 BsmFI GGGAC (N10/14) 5 +4 NEB SAGE MmeI TCCRAC (N20/18) 5.5 -2 NEB LongSage EcoP15I CAGCAG (N25/27) 6 +2 homemade SuperSage BceAI ACGGC (N12/14) 5 +2 Bce83I CTTGAG (N16/14) 6 -2 AcuI CTGAAG (N16/14) 6 -2 AarI CACCTGC(N4/8) 7 +4 SceI TAGGG_ATAA^CAGGGTAAT 18 -4 BsaXI (N9/12)AC(N5)CTCC(N10/7) 6+3-3 NEB Velculescu etal. Science. 1995 270:484. SahaS,etal. Nat Biotec. 2002 20:508 Matsumura etal.PNAS 2003 100:15718
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Mirror world : enzyme, parasite, & predator resistance & access 2 n diastereomers (n chiral atoms) L-amino acids & D-ribose (rNTPs, dNTPs) Transition: EF-Tu, peptidyl transferase, DNA-ligase D-amino acids & L-ribose (rNTPs, dNTPs) Dedkova, et al. (2003) Enhanced D-amino acid incorporation into protein by modified ribosomes. J Am Chem Soc 125, 6616-7
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Free up 1 to 15 codons in vivo M. luteus missing 6 codons: UUA(L), CUA(L), AUA(I), GUA(V), CAA(Q), AGA(R). 3 4 1 2 * * * * * *
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Up to 760K Oligos/Chip 18 Mbp for $1K raw (6-18K genes) <1K Oxamer Electrolytic acid/base 8K Atactic/Xeotron/Invitrogen Photo-Generated Acid Sheng, Zhou, Gulari, Gao (U.Houston) 24K Agilent Ink-jet standard reagents 48K Febit 100K Metrigen 380K Nimblegen Photolabile 5'protection Nuwaysir, Smith, Albert Tian, Gong, Church ~5000 lower oligo costs
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Improving DNA synthesis accuracy Method Bp/error Chip assembly only 160 Hybridization-selection 1,400 MutS-gel-shift 10,000 PCR 35 cycles 10,000 MutHLS cleavage 100,000 Tian & Church 2004 Nature Carr & Jacobson 2004 NAR Smith & Modrich 1997 PNAS http://www.invitrogen.com/content.cfm?pageid=453
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CAD-PAM: Computer aided Design - Polymerase Assembly Multiplexing For tandem, inverted and dispersed repeats: Focus on 3' ends, hierarchical assembly, size-selection and scaffolding. Mullis 1986 CSHSQB, Dillon 1990 BioTech, Stemmer 1995 Gene Tian et al. 2004 Nature, Kodumal et 2004 PNAS 50 75 125 225 425 825 … 100*2^(n-1)
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Genome assembly 0 1 2 3 4 PAM cycle# 5 50 75 125 225 425 #bp 825 50 HS PAM 425 MutS PAM 10K anneal 100K red 5Mbp USER-S1 USER-S1 USER-5'only One pool 480 pools 480 genomic 48 1 of 117K universal primers primer pairs HS=Hybridization-Selection USER=Uracil DNA glycosylase &EndoVIII to remove flanking primer pairs PCR in vitro Isaacs, Carr, Emig, Gong, Tian, Jacobson, Church in vivo
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Genome assembly alternatives 1. tet Serial electroporation: 48 stages: 1 strain (1.6 days/stage) vs. Conjugation: 7 stages: 48 > 24 > 12 > 6 > 3 > 2 > 1 strains 3. tet 2. kan Reppas & Church
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All 30S-Ribosomal-protein DNAs (codon re-optimized) Tian, Gong, Sheng, Zhou, Gulari, Gao, Church 1.7 kb 0.3 kb s19 0.3kb Nimblegen 95K chip Atactic <4K chip 14.6 kb
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Extreme mRNA makeover for protein expression in vitro RS-2,4,5,6,9,10,12,13,15,16,17,and 21 detectable initially. RS-1, 3, 7, 8, 11, 14, 18, 19, 20 initially weak or undetectable. Solution: Iteratively resynthesize all mRNAs with less mRNA structure. Tian & Church Western blot based on His-tags
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Genome engineering: Cross-feeding Auxotrophs trp/ tyrA pair of genomes shows the best co-growth (syntrophs) Reppas & Lin First Passage SecondPassage
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Co-evolution of syntrophic Trp-/Tyr- genome pair
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# of bases sequenced (total Mbp)23 (no) 10.8 (yes) # bases sequenced (unique)73 b 4.7 Mb (72%) Average fold coverage 324,000 2.3 Pixels used per bead (analysis) 3.6 3.6 Read Length (bp) 14 24 Indels 0.6% ? Substitutions (raw error-rate) 4e-5 1e-2 Throughput (kb/min) 360 10 Speed/cost ratio relative to 1100 32 current ABI capillary sequencing @ 0.75 kb/min/device Plone-bead FISSeq SBE SBL Consider amplification, homopolymer, context errors? Shendure & Porreca
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Plone analysis of synthetic evolved E.coli Tyr- / Trp- pair 374,449 G>A MhpT 5'UTR 3-hydroxyphenylpropionic acid transport 986,327 T>G OmpF Promoter-10 Outer membrane porin 1,990,682 G>A PgsA Arg>Cys Essential phospholipid synthesis protein 3,599,626 G>C FtsX Leu>Val Essential cell division protein 3,957,957 C>T PpiC 5'UTR Peptidyl-prolyl cis-trans isomerase (stress) 4,002,444 G>C YigI Arg->Gly Unknown conserved protein Reppas, Shendure, Porreca
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Harvard iGEM Tag! / BioWire (Signal Transfer)Tag! / BioWire (Signal Transfer) Paula, Patrick, Jenny, Kang-Xing Thermal / Diagnostic DetectionThermal / Diagnostic Detection Chris, Ives, Thomas, Danny, Connie Cell Density DetectionCell Density Detection Yin, Hing, Orr, Sasha June 2 10:00-10:45 (George, Biolabs Main Lecture Hall) Overview of synthetic biology -- Slides [1] [1] June 6 9:30-11:00 (George) Risks and Rewards -- Slides[2] [2]
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Defense not offense (albeit a perfect defense can allow first strikes) How would you make cells resistant to all viruses (phages)? Auto-destruct at a specific conditions (temperature) Toxin-antitoxin pairs: RelB/E, MazE/, yeeU/V, CcdB inhibits GyrA Auxotrophs (metabolic dependencies) Inexpensive monitoring & diagnostics, bio-weather-map Optimal biosynthesis e.g. artemesinin (malaria) Explore epitopes & vaccines
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