MOLECULAR COMPUTING REFERENCES “Research on bacterial signal transduction is shifting from a focus on individual genes and proteins in vitro to the study of whole systems in vivo. Each component is now regarded as a node, the essential character of which can only be fully appreciated in terms of its connections to other nodes. In this context, an individual E. coli cell is a network with about 108 nodes composed of the products of about 103 different genes. Analyses of the structure–function relationships involved in paradigmatic signaling pathways such as Lac, Che, or PhoQ/P have revealed crucial elements of molecular logic. The next task is to understand how these elements are connected to form a dynamic, adaptive cell. How is information converted into knowledge, and how is knowledge sorted, evaluated and combined to guide action, morphogenesis and growth?” Melinda D. Baker and Jeffry B. Stock (2007) Signal Transduction: Networks and Integrated Circuits in Bacterial Cognition Current Biology Vol 17 No 23, R1021-R1024. Christopher M.Waters and Bonnie L. Bassler (2005) Quorum Sensing: Cell-toCell Communication in Bacteria. Annual Review of Cell and Developmental Biology. Vol. 21: 319-346 Nadell CD, Bucci V, Drescher K, Levin SA, Bassler BL, Xavier JB. (2013) Cutting through the complexity of cell collectives. Proc R Soc B 280: 20122770. http://dx.doi.org/10.1098/rspb.2012.2770 Rutherford ST, Bassler BL. (2012) Bacterial quorum sensing: its role in virulence and possibilities for its control. Cold Spring Harb Perspect Med. 2 pii: a012427. Bassler BL. (2010) Small cells--big future. Mol Biol Cell. 21: 3786-3787. Mehta P, Goyal S, Long T, Bassler BL, Wingreen NS. (2009) Information processing and signal integration in bacterial quorum sensing. Mol Syst Biol. 5: 325. Ng WL, Bassler BL. (2009) Bacterial quorum-sensing network architectures. Annu Rev Genet. 43: 197-222. Alexei Kurakin, “Self-Organization vs. Watchmaker: Stochastic Dynamics of Cellular Organization” Biological Chemistry, 2005, 386: 247–254; p. 250. “Defying the ideas of design and clockwork determinism, a leitmotiv of the latest experimental research are the ubiquitous observations of self-organization and stochasticity that appears to emerge as general principles underlying the dynamics and organization of life at all scales. Stochastic molecular motors, stochastic enzymes, stochastic self-organization of cytoskeleton structures, sub-cellular and sub-nuclear compartments, stochastic self-organization of macromolecular complexes mediating transcription, DNA repair and chromatin structure/function, stochastic gene expression and stochastic cellular responses are poorly compatible with the familiar notions of design, programs, instructions and codes, and their systematic appearance is a call for active efforts to loosen the grip of the conventional mechanistic models and concepts in a search for an alternative and more adequate description of life systems.” (3) Kurakin, above “In installment five, I began exploring an alternative view of life as an emergent phenomenon within an overall framework of physical emergence that has been developed by investigators in condensedmatter physics over the past half century.” Barham ”No one has discussed the implications of the just-in-time self-organization of cellular structures with greater emphasis, eloquence, and profundity than Alexei Kurakin.” L.Landweber, L.Kari. The evolution of cellular computing: nature's solution to a computational problem. Biosystems 52(1999) L.Kari, L.F.Landweber. Computational power of gene rearrangement. Proc. DNA Computing 5, DIMACS Series, 54(2000) L.Kari, J.Kari, L.Landweber. Reversible molecular computation in ciliates. In Jewels are Forever, Springer-Verlag (1999) Mark J. Schnitzer Biological computation: Amazing algorithms Nature 416, 683-683 doi:10.1038/416683a W hen can a physical system be said to perform a computation? In the broadest sense, every physical system performs a computation by realizing a solution to the dynamic equations that govern its physical behaviour. However, physical computing is more interesting in the narrower domain in which a set of physical variables represents the values of another set of mathematical ones. A physical variable might be a voltage within a digital computer, the height of a stack of poker chips, or a chemical concentration in a biological cell. These variables are then dynamically transformed by physical processes, in a way that represents algorithmic manipulation of the mathematical variables. Mark J. Schnitzer Ramiz Daniel, Jacob R. Rubens, Rahul Sarpeshkar & Timothy K. Lu (15 May 2013) Synthetic analog computation in living cells Nature 497, 619-623 doi:10.1038/nature12148 Yaakov Benenson, Tamar Paz-Elizur, Rivka Adar, Ehud Keinan, Zvi Livneh & + et al. (22 November 2001) Programmable and autonomous computing machine made of biomolecules Nature 414, 430-434 doi:10.1038/35106533 Lila Kari, Grzegorz Rozenberg (October 2008). "The Many Facets of Natural Computing". Communications of the ACM 51: pp.72–83. Leandro Nunes de Castro (March 2007). "Fundamentals of Natural Computing: An Overview". Physics of Life Reviews 4: pp.1–36. based on template guided recombination – this is state transition table of an automata. However, while classical automata are deterministic (or indeterministic in a weak sense of choice between known states) biological systems are indeterministic in a strong sense, that is their transition can be to states which are not known in advance (new states for the system). As this kind of transition does not happen very often, such indeterminism leads to development. It is based on the fact that living organisms are open systems, and environment is an unlimited source of inputs. Nakagawa, H., Sakamoto, K., Sakakibara, Y. Development of an in vivo computer based on Escherichia Coli. In LNCS 3892, pages 203-212, Springer, 2006: “Other approaches to cellular computing include developing an in vivo programmable and autonomous finite-state automaton with E. coli,[45] and designing and constructing in vivo cellular logic gates and genetic circuits that harness the cell's existing biochemical processes (see for example [46][47]).” “Our fundamental idea to develop a programmable and autonomous finite-state automata on E. coli is that we first encode an input string into one plasmid, encode state-transition functions into the other plasmid, and introduce those two plasmids into an E. coli cell by electroporation. Second, we execute a protein-synthesis process in E. coli combined with four-base codon techniques to simulate a computation (accepting) process of finite automata, which has been proposed for in vitro translation-based computations in [8]. This approach enables us to develop a programmable in vivo computer by simply replacing a plasmid encoding a state-transition function with others. Further, our in vivo finite automata are autonomous because the protein-synthesis process is autonomously executed in the living E. coli cell. We show some successful experiments to run an in vivo finite-state automaton on E. coli.” Zabet NR, Hone ANW, Chu DF Design principles of transcriptional logic circuits. In Artificial Life XII Proceedings of the Twelfth International Conference on the Synthesis and Simulation of Living Systems, pages 186-193. MIT Press, August 2010. Zabet NR Towards Modular, Scalable and Optimal Design of Transcriptional Logic Systems. 2010. At a minimum, one must distinguish between “self-assembly” (or “self-ordering”), which may be described in “downhill” (exergonic) terms, and “self-organization,” which cannot be adequately so described. On this important topic, see: Julianne D. Halley and David A. Winkler, “Consistent Concepts of Self-Organization and Self-Assembly,” Complexity, 2008, 14(2): 10–17. Shapiro, J. A. (2011). Evolution: A View from the 21st Century. Upper Saddle River, New Jersey, FT Press Science. ISBN 978-0132780933. Living cells and organisms are cognitive (sentient) entities that act and interact purposefully to ensure survival, growth, and proliferation. They possess corresponding sensory, communication, information processing, and decisionmaking capabilities. (p. 143) One of the most profound lessons from the past six decades of molecular cell biology is that all aspects of cell functioning and cellular biochemistry are subject to regulation. (p.69) Without an elaborate sensory apparatus to pick up signals about chemicals in the environment (nutrients, poisons, signals emitted by other cells) or to keep track of intracellular events (DNA replication, organelle growth, oxidative damage), a cell’s opportunity to proliferate or contribute to whole-organism development would be severely restricted. Life requires cognition at all levels [40, 41].” Shapiro p. 7 “The selected cases just described are examples where molecular biology has identified specific components of cell sensing, information transfer, and decisionmaking processes. In other words, we have numerous precise molecular descriptions of cell cognition, which range all the way from bacterial nutrition to mammalian cell biology and development. The cognitive, informatic view of how living cells operate and utilize their genomes is radically different from the genetic determinism perspective articulated most succinctly, in the last century, by Francis Crick’s famous “Central Dogma of Molecular Biology.” “ p. 24 Bray, D. (2009). Wetware: A Computer in Every Living Cell New Haven, CT, Yale University Press. ISBN 978-0300141733. LUCA CARDELLI and GIANLUIGI ZAVATTARO Turing universality of the Biochemical Ground Form, Mathematical Structures in Computer Science / Volume 20 / Special Issue 01 / February 2010, pp 45-73 Zavattaro’s research was partially funded by ‘Progetto Strategico’ CompReNDe: Compositional and executable Representations of Nano Devices. BEN-JACOB & ROGLIC Roglic, Darko in Information and Computation SUPER-RECURSIVE FEATURES OF EVOLUTIONARY PROCESSES AND THE MODELS COMPUTATIONAL EVOLUTION Ben-Jacob, E. (1998) Bacterial wisdom, Godel’s theorem and creative genomic webs. Physica A 248, 57-76 Ben Jacob, E. (2003) Bacterial Self-Organization: Co-Enhancement of Complexification and Adaptability in a Dynamic Environment Phil. Trans. R. Soc. Lond. A, 361:1283-1312 Ben-Jacob, E., Becker, I., Y. Shapira. Y. (2004) Bacteria Linguistic Communication and Social Intelligence. Trends in Microbiology, Vol 12/8 pp 366-372 FOR Ben Jacob, E. and Shapira, Y. (2005) Meaning-Based Natural Intelligence Vs. Information Based Artificial Intelligence. Cradle of Creativity Ben Jacob, E., Shapira, Y., Tauber, A.I. (2006) Seeking the Foundations of Cognition in Bacteria Physica A vol 359 ; 495-524, Ben Jacob, E. (2008). Social behaviour of bacteria: from physics to complex organization. The European Physical Journal B