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Thanks to: Agencourt, Ambergen, Atactic, BeyondGenomics, Caliper, Genomatica, Genovoxx, Helicos, MJR, NEN, Nimblegen, ThermoFinnigan, Xeotron/Invitrogen For more info see: arep.med.harvard.edu DOE Wed 3-Nov-2004 11:30 AM Analysis & Synthesis of Omes
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Systems Biology Loop Syntheses & Perturbations Models Experimental designs (Systematic) Data Proteasome targeting Genome engineering Metabolic optimality Flux & Competitive growth DNA & RNA Polony-Seq Synthetic Biology Tools
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DOE Synthetic Genomes: Why? Cheaper/faster "standard biology", hypothesis testing Systems Biology: Multiple simultaneous tests Viruses: Aid strain transfer; generate variants, new haplotypes Anti-viral vaccines and therapeutics (including variants) In vitro: Make products toxic in E.coli. Microbes: Interspecific hybrids (e.g. codon usage) Structural biology: variants Rapid vaccine response to engineered bioterrorism. Cell-mediated immunity + humoral. Fix mismatch between genome analysis & synthesis
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DOE Synthetic Genomes: Why? In vitro Microbial & Human Antimutators Artificial ecosystems (laboratory scales) Energy aiding pathway improvement Instrustrial production: Enzymes, SingleCellProtein, Protein- drugs Remediation: Hybrid genomes (opt. codons), combinatorial pathway (Maxygen & Diversa). Xylose & Oil Pharmaceuticals: Combinatorial syntheses Nano science Combinatorial syntheses, Complex nanosystems, more general nanoassembly (in reach of polymerases and ribosome-like factories) Health research: 10X faster results per current $ (cost/benefit) Hypothesize & test unknown gene combinations Synthetic standards (arrays, MS, quantitation, etc) Agriculture: salt, cold, drought, pest tolerant hybrid genomes
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Motif Co-occurrence, comparative genomics, RNA clusters, and/or ChIP 2 -location data P= 10 -6 to 10 -11 Genome Res. 14:201–208 Bulyk, McGuire,Masuda,Church
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Synthetic testing of DNA motif combinations 1.3 2.4 (1.3 in argR) 1.1 1.3 0.7 2.5 0.2 1.4 1.4 3.5 RNA Ratio (motif- to wild type) for each flanking gene Bulyk, McGuire,Masuda,Church Genome Res. 14:201–208
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Synthetic Genomes & Proteomes. Why? Test or engineer cis-DNA/RNA-elements Access to any protein (complex) including post-transcriptional modifications Affinity agents for the above. Mass spectrometry standards, protein design Utility of molecular biology DNA-RNA-Protein in vitro "kits" (e.g. PCR, SP6, Roche) Toward these goals design a chassis: 115 kbp genome. 150 genes. Nearly all 3D structures known. Comprehensive functional data.
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(PURE) translation utility Removing tRNA-synthetases, translational release-factors, RNases & proteases Selection of scFvs specific for HBV DNA polymerase using ribosome display. Lee et al. 2004 J Immunol Methods. 284:147 Programming peptidomimetic syntheses by translating genetic codes designed de novo. Forster et al. 2003 PNAS 100:6353 High level cell-free expression & specific labeling of integral membrane proteins. Klammt et al. 2004 Eur J Biochem 271:568 Cell-free translation reconstituted with purified components. Shimizu et al. 2001 Nat Biotechnol. 19:751-5.
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in vitro genetic codes 5' mS yU eU UGG UUG CAG AAC... GUU A 3' GAAACCAUG fMTNVE | | | 5' Second base 3' U A C C U mS yU eU A C U G A Forster, et al. (2003) PNAS 100:6353-7 80% average yield per unnatural coupling. bK = biotinyllysine, mS = Omethylserine eU=2-amino-4-pentenoic acid yU = 2-amino-4-pentynoic acid
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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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Forster & Church Oligos for 150 & 776 synthetic genes (for E.coli minigenome & M.mobile whole genome respectively)
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Up to 760K Oligos/Chip 18 Mbp for $700 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
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Improve DNA Synthesis Cost Synthesis on chips in pools is 5000X less expensive per oligonucleotide, but amounts are low (1e6 molecules rather than usual 1e12) & bimolecular kinetics slow with square of concentration decrease!) Solution: Amplify the oligos then release them. 10 50 10 => ss-70-mer (chip) 20-mer PCR primers with restriction sites at the 50mer junctions Tian, Gong, Sheng, Zhou, Gulari, Gao, Church => ds-90-mer => ds-50-mer
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Improve DNA Synthesis Accuracy via mismatch selection Tian & Church Other mismatch methods: MutS (&H,L)
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Genome assembly Moving forward: 1. Tandem, inverted and dispersed repeats (hierarchical assembly, size-selection and/or scaffolding) 2. Reduce mutations (goal <1e-6 errors) to reduce # of intermediates 3. >30 kbp homologous (Nick Reppas) 4. Phage integrase site-specific recombination, also for counters. Stemmer et al. 1995. Gene 164:49-53;Mullis 1986 CSHSQB. 50 75 125 225 425 825 … 100*2^(n-1)
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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
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Improving synthesis accuracy 9-fold Method Total bp # Clones Trans- ition Trans- versionDeletionAddition Bp/error Hyb selection, PCR2364197352 1391 Gel selection, PCR24546352812113 455 No selection, ligation +PCR60932566224 160 No selection, PCR9243212513191 159 Tian & Church
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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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Systems Biology Loop Syntheses & Perturbations Models Experimental designs (Systematic) Data Proteasome targeting Genome engineering Metabolic optimality Flux & Competitive growth DNA & RNA Polony-Seq Synthetic Biology Tools
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Why sequence? Cancer: mutation sets for individual clones, loss-of-heterozygosity Pathogen "weather map", biowarfare sensors RNA splicing & chromatin modification patterns. Synthetic biology & lab selections Antibodies or "aptamers" for any protein B & T-cell receptor diversity: Temporal profiling, clinical Preventative medicine & genotype–phenotype associations Cell-lineage during development Phylogenetic footprinting, biodiversity Shendure et al. 2004 Nature Rev Gen 5, 335.
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Sequencing single molecules Ecosystem studies really need single-cell amplification because of multiple chromosomes (& RNAs) (Even an 80% genome coverage is better than 100 kb BACs)
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Single bacterial chromosome amplification Ratio to unamplified hybridization along the chromosome of Escherichia & Prochlorococus on Affymetrix chips.
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Convergence on non-electrophorectic tag sequencing methods? Tag >400 14-26 20 100 26 bp (2-ends) EST SAGE MPSS 454 Polony-Seq Single-molecule vs. amplified single molecule. Array vs. bead packing vs. random Rapid scans vs. long scans (chemically limited, 454) Number of immobilized primers: 0: Chetverin'97 "Molecular Colonies" 1: Mitra'99 > Agencourt "Bead Polonies" 2: Kawashima'88, Adams'97 > Lynx/Solexa: "Clusters" http://arep.med.harvard.edu/Polonator/Plone.htm
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Polony Fluorescent In Situ Sequencing Libraries Greg Porreca Abraham Rosenbaum 1 to 100kb Genomic M L R M PCR bead Sequencing primers Selector bead 2x20bp after MmeI ( BceAI, AcuI) Dressman et al PNAS 2003 emulsion
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Cleavable dNTP-Fluorophore (& terminators) Mitra,RD, Shendure,J, Olejnik,J, Olejnik,EK, and Church,GM (2003) Fluorescent in situ Sequencing on Polymerase Colonies. Analyt. Biochem. 320:55-65 Reduce or photo- cleave
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0.5% of full gel area Polony-FISSeq: up to 2 billion beads/slide
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Cy5 primer (570nm) ; Cy3 dNTP (666nm) Jay Shendure
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# of bases sequenced (total)23,703,953 # bases sequenced (unique)73 Avg fold coverage324,711 X Pixels used per bead (analysis)~3.6 Read Length per primer14-15 bp Insertions 0.5% Deletions 0.7% Substitutions (raw) 4e-5 Throughput:360,000 bp/min Polony FISSeq Stats Current capillary sequencing 1400 bp/min (600X speed/cost ratio, ~$5K/1X) (This may omit: PCR, homopolymer, context errors) Shendure
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Systems Biology Loop Syntheses & Perturbations Models Experimental designs (Systematic) Data Proteasome targeting Genome engineering Metabolic optimality Flux & Competitive growth DNA & RNA Polony-Seq Synthetic Biology Tools
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High accuracy special case: homopolymers (e.g. AAA, CC, etc.) Use "compressed" tags, ACG = ACCG=ACCCG Quantitate incorporation Reversible terminators "Wobble sequencing" All of these work. Maintenance of amplification fidelity using linear amplification from initial genomic fragment
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"Wobble sequencing" for homopolymers 6 positions * 16 primers * 4 dNTPs => 13 bp (paired ends) CCTCATTCTCT AA + dATP (then C, …) CCTCATTCTCT AC + dATP (then C, …)... CCTCATTCTCTnnAA + dATP (then C, …)... CCTCATTCTCTnnNNnnNNnnTT + dATP (then C, …) 4.5/64 bp/cycle (for wobble sequencing) vs. 2.5/4 bp/cycle (for simple sequential base-extension)
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