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Lecture # 1. The Grand Schema of Things. Outline. The grand scheme of things Some features of genome-scale science The systems biology paradigm Building foundations Where does (Molecular) Systems Biology fit in to biological hierarchy. How does systems biology fit in?.
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Lecture # 1 The Grand Schema of Things
Outline • The grand scheme of things • Some features of genome-scale science • The systems biology paradigm • Building foundations • Where does (Molecular) Systems Biology fit in to biological hierarchy
How does systems biology fit in? THE GRAND SCHEMA OF SCIENCE
Gregor Mendel (1822-1884) • Established the existence of discrete inherited elements, now called genes, that determined organism form and function (i.e., the phenotype) • The genotype/phenotype relationship becomes a fundamental concept in biology
Fast Forward to the 1950s:genes and human disease • Linus Pauling: Hemoglobin and Sickle-cell anemia • Monogeneic traits can be easily traced • about 150-200 that can be tested for • However, most traits are polygeneic and complex
Fast Forward to 1995:birth of the genome era • Whole genome sequences become available • “All” genetic elements in a genome can be identified and characterized • in principle but in practice 2/3 • Genome scale science enabled Craig Venter
Putting the Pieces Together:Genome-scale Network Reconstructions, 1997-2000 • Organism-specific genome-scale metabolic networks • E. coli, H. influenzae, H. pylori • The first high throughput in silico biologists Jeremy Edwards Christophe Schilling
Extended to Eukaryotes (2001-03) • Yeast, w/Jens Nielsen Lab • Iman Famili/Jochen Forster
Global Metabolic Map Comprehensively represents known reactions in human cells Reactions (3,311) Pathways (98) Genes (1,496) Transcripts (1,905) Proteins (2,004) Human metabolism: RECON 1 (2005-07) Compounds (2,712) Compartments (7)
Stoichiometric Matrix reaction metabolite S = • Network reconstruction is a BiGG knowledge base • Conversion of knowledge into mathematical format • Birth of genome-scale (metabolic) systems biology • Puts a mechanistic basis for the genotype-phenotype relationship • Dual causality needs to be accounted for • different than physics a 100 years ago Mathematical representation Network map
Mechanistic genotype-phenotype relationships Concepts in genome-scale science
Molecular to Systems Biology Nature Biotechnology, 18:1147, 2000
Pathway in the Context of a System Methanosarcina barkeri metabolism Examining the Properties of an Individual Pathway L-serine Biosynthesis
The intracellular environment is crowed and interconnected placing severe constraints on achievable physiological states
Hierarchy in systems biology Chemical causation: Can apply P/C laws and get causality on a small scale Ludwig Boltzmann (1844-1906) Charles Darwin (1809-1882) Systems biology: emphasis on modules and understanding of how coherent physiological functions arise from the totality of molecular components Biological causation; genome-scale changes and description of 1000’s of variables. Network and econometric type analysis methods
Building the G/P-relationship: integrated network reconstructions conceptual operational M Matrix OME Matrix ME Matrix Meta-structure E Matrix O Matrix
Reconstruction is iterative:History of the E. coli Metabolic Reconstruction Jeff Orth Adam Feist Ines Thiele Jeremy Edwards Jennie Reed Jay Keasling AmitVarma
Systems Biology Paradigm:components -> networks -> computational models -> phenotypes Palsson,BO; Systems Biology, Cambridge University Press 2006
Our Systems Biology Series Data types -- 211 Reconstruction– 211/212 In silico analysis– 212/213 Tailoring to tissues Drug response phenotypes Synthetic Biology Metabolic Engineering Adaptive evolution Disease progression Differentiation SMILEY
Towards ‘principles’for molecular biology on genome scale BUILDING FOUNDATIONS
Emerging Axioms of COBRA • Axiom #1: All cellular functions are based on chemistry. • Axiom #2: Annotated genome sequences along with experimental data enable the reconstruction of genome-scale metabolic networks. • Axiom #3: Cells function in a context-specific manner. • Axiom #4: Cells operate under a series of constraints. • Axiom #5: Mass (and energy) is conserved. • Axiom #6: Cells evolve under a selection pressure in a given environment. This statement has implicit optimality principles built into it FEMS, 583:3900, 2009
WHERE IN THE BIOLOGICAL HIERARCHY IS (MOLECULAR) SYSTEMS BIOLOGY?
Biological Scales and Systems Analysis ecology physiology immunology Molecular systems biology Courtesy of Vito Quaranta, MD; Vanderbilt University, Nashville, TN
Multi-scale view of E. coli colony cell nucleoid macromolecule
Summary • Genes are quanta of inherited information • These quanta influence the functions of organisms • The genotype-phenotype relationship is foundational to biology • Monogenic diseases/traits can easily be traced • Most traits are poly-genic • Full sequencing of genomes gave us the possibility to enumerate all the genes that make up an organism • Systems biology rose to meet the challenge of figuring out how all genes and the biochemical properties of the gene products come together to produce organism functions • The (metabolic) genotype-phenotype relationship now has a mechanistic basis! • Fundamentals of the field are emerging