Xenobiology: State-of-the-Art, Ethics, and Philosophy of New-to-Nature Organisms
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The basic chemical constitution of all living organisms in the context of carbon-based chemistry consists of a limited number of small molecules and polymers. Until the twenty-first century, biology was mainly an analytical science and has now reached a point where it merges with engineering science, paving the way for synthetic biology. One of the objectives of synthetic biology is to try to change the chemical compositions of living cells, that is, to create an artificial biological diversity, which in turn fosters a new sub-field of synthetic biology, xenobiology. In particular, the genetic code in living systems is based on highly standardized chemistry composed of the same “letters” or nucleotides as informational polymers (DNA, RNA) and the 20 amino acids which serve as basic building blocks for proteins. The universality of the genetic code enables not only vertical gene transfer within the same species but also horizontal gene transfer across biological taxa, which require a high degree of standardization and interconnectivity. Although some minor alterations of the standard genetic code are found in nature (e.g., proteins containing non-conical amino acids exist in nature, and some organisms use alternated coding systems), all structurally deep chemistry changes within living systems are generally lethal, making the creation of artificial biological system an extremely difficult challenge.
In this context, one of the great challenges for bioscience is the development of a strategy for expanding the standard basic chemical repertoire of living cells. Attempts to alter the meaning of the genetic information stored in DNA as an informational polymer by changing the chemistry of the polymer (i.e., xeno-nucleic acids) or by changes in the genetic code have already yielded successful results. In the future this should enable the partial or full redirection of the biological information flow to generate “new” version(s) of the genetic code derived from the “old” biological world.
In addition to the scientific challenges, the attempt to increase biochemical diversity also raises important ethical and philosophical issues. Although promotors of this branch of synthetic biology highlight the many potential applications to come (e.g., novel tools for diagnostics and fighting infection diseases), such developments could also bring risks affecting social, political, and other structures of nearly all societies.
KeywordsEthics New-to-nature Non-canonical amino acids Philosophy Synthetic biology Xenobiology
The thoughts and ideas presented here are largely results of our interaction with Philippe Marlière, Sven Panke, Piet Herdewijn, Carlos-Acevedo Rocha, and Dirk Schulze-Makuch. Another very fortunate circumstance was that we worked together in EU-FP7 founded project METACODE (289572) whereby we could start to implement some of our conceptual ideas in the field of xenobiology. MS and NB also acknowledge support form EC FP7 project SYNPEPTIDE (613981) and MS acknowledges EC FP7 project SYNENERGENE (321488).
- 2.Venter JC (2013) Life at the speed of light – from the from the double helix to the dawn of digital life. Viking Penguin, New YorkGoogle Scholar
- 3.Balter M (2015) Farming was so nice, it was invented at least twice. Science news, from http://www.sciencemag.org/news/2013/07/farming-was-so-nice-it-was-invented-least-twice
- 6.de Lorenzo V (2010) Environmental biosafety in the age of synthetic biology: do we really need a radical new approach? Environmental fates of microorganisms bearing synthetic genomes could be predicted from previous data on traditionally engineered bacteria for in situ bioremediation. BioEssays 32(11):926–931CrossRefGoogle Scholar
- 13.Church G, Regis E (2012) Regenesis: how synthetic biology will reinvent nature and ourselves. Basic Books, New YorkGoogle Scholar
- 14.Multhauf RP (1966) The origins of chemistry. Oldbourne, LondonGoogle Scholar
- 15.Fisher E (1907) Synthetic chemistry in its relation to biology (Faraday Lecture). J Chem Soc Chem Commun 91:1749–1765Google Scholar
- 19.Acevedo-Rocha CG (2016) The synthetic nature of biology. In: Hagen K, Engelhard M, Toepfer G (eds) Ambivalences of creating life: societal and philosophical dimensions of synthetic biology. Springer, Switzerland, pp 9–53Google Scholar
- 22.Hutchison CA III, Chuang RY, Noskov VN, Assad-Garcia N, Deerinck TJ, Ellisman MH, Gill J, Kannan K, Karas BJ, Ma L, Pelletier JF, Qi ZQ, Richter RA, Strychalski EA, Sun L, Suzuki Y, Tsvetanova B, Wise KS, Smith HO, Glass JI, Merryman C, Gibson DG, Venter JC (2016) Design and synthesis of a minimal bacterial genome. Science 351(6280):aad6253Google Scholar
- 23.Gibson DG, Glass JI, Lartigue C, Noskov VN, Chuang RY, Algire MA, Benders GA, Montague MG, Ma L, Moodie MM, Merryman C, Vashee S, Krishnakumar R, Assad-Garcia N, Andrews-Pfannkoch C, Denisova EA, Young L, Qi ZQ, Segall-Shapiro TH, Calvey CH, Parmar PP, Hutchison CA 3rd, Smith HO, Venter JC (2010) Creation of a bacterial cell controlled by a chemically synthesized genome. Science 329(5987):52–56CrossRefGoogle Scholar
- 24.SCHER, SCENIHR, SCCS (2014) Opinion on synthetic biology I definition. Available at http://ec.europa.eu/health/scientific_committees/emerging/docs/scenihr_o_044.pdf
- 34.Kimoto M, Cox RS 3rd, Hirao I (2011) Unnatural base pair systems for sensing and diagnostic applications. Expert Rev Mol Diagn 11(3):321–331Google Scholar
- 36.SCHER, SCENIHR, SCCS (2015) Opinion on synthetic biology II - risk assessment methodologies and safety aspects. Available at http://ec.europa.eu/health/scientific_committees/consultations/public_consultations/scenihr_consultation_26_en.htm
- 39.Schmidt M (2013) Safeguarding the genetic firewall with xenobiology. 21st century borders/synthetic biology: focus on responsibility and governance, Institute on Science for Global Policy, Tucson, ArizonaGoogle Scholar
- 41.Beiboer SH, van den Berg B, Dekker N, Cox RC, Verheij HM (1996) Incorporation of an unnatural amino acid in the active site of porcine pancreatic phospholipase A2. Substitution of histidine by 1,2,4-triazole-3-alanine yields an enzyme with high activity at acidic pH. Protein Eng 9(4):345–352CrossRefGoogle Scholar
- 42.Budisa N, Minks C, Alefelder S, Wenger W, Dong F, Moroder L, Huber R (1999) Toward the experimental codon reassignment in vivo: protein building with an expanded amino acid repertoire. FASEB J 13(1):41–51Google Scholar
- 55.Nunes-Alves C (2015) GMOs in lockdown. Nat Rev Microbiol 13:3443Google Scholar
- 67.EGE (2009) Ethically speaking. Available at http://ec.europa.eu/archives/bepa/european-group-ethics/docs/ethic_speak_n13_en.pdf
- 68.EGE (2009) Ethics of synthetic biology. Available at http://ec.europa.eu/bepa/european-group-ethics/docs/opinion25_en.pdf
- 69.De Vriend H (2006) Constructing life. Early social reflections on the emerging field of synthetic biology. Available at http://www.rathenau.nl/uploads/tx_tferathenau/WED97_Constructing_Life_2006.pdf
- 70.European Commission (2010) Synthetic biology from science to governance. Workshop organised by the European Commission’s Directorate-General for Health & Consumers, BrusselsGoogle Scholar
- 72.SCHER, SCENIHR, SCCS (2015) Opinion on synthetic biology III: research priorities. Available at http://ec.europa.eu/health/scientific_committees/consultations/public_consultations/scenihr_consultation_28_en.htm
- 74.Boldt J, Müller O, Maio G (2009) Synthetische Biologie Eine ethisch-philosophische Analyse. Bundesamt für Bauten und Logistik, BernGoogle Scholar
- 81.CBD (2012) Nagoya Protocol on access to genetic resources and the fair and equitable sharing of benefits arising from their utilization to the convention on biological diversity. Available at https://www.cbd.int/abs/doc/protocol/nagoya-protocol-en.pdf
- 82.Trojok RD (2014) Bio-commons whitepaper. Available at http://bioartsociety.fi/Bio-Commons_Whitepaper.pdf