摘要：Cooperation is ubiquitous in biological sys- tems. However, if natural selection favors traits that confer an advantage to one individual over another, then helping others would be paradoxical. Nevertheless, cooperation persists and is critical in maintaining homeostasis in systems ranging from populations of bacteria to groupings of mammals. Developing an understanding of the dynamics and mechanisms by which cooperation operates is critical in understanding ecological and evolutionary relationships. Over the past decade, synthetic biology has emerged as a powerful tool to study social dynamics. By engineering rationally controlled and modulatable beha- vior into microbes, we have increased our overall under- standing of how cooperation enhances, or conversely constrains, populations. Furthermore, it has increased our understanding of how cooperation is maintained within populations, which may provide a useful framework to influence populations by altering cooperation. As many bacterial pathogens require cooperation to infect the host and survive, the principles developed using synthetic biology offer promise of developing novel tools and strategies to treat infections, which may reduce the use of antimicrobial agents. Overall, the use of engineered cooperative microbes has allowed the field to verify existing, and develop novel, theories that may govern cooperative behaviors at all levels of biology.

摘要：Microalgal oils, depending on their degree of unsaturation, can be utilized as either nutritional supplements or fuels; thus, a feedstock with genetically designed and tunable degree of unsaturation is desirable to maximize process efficiency and product versatility. Systematic profiling of ex vivo （in yeast）, in vitro, and in vivo activities of type-2 diacylglycerol acyltransferases in Nannochloropsis oceanica （NoDGAT2s or NoDGTTs）, via reverse genetics, revealed that NoDGAT2A prefers saturated fatty acids （SFAs）, NoDGAT2D prefers monounsaturated fatty acids （MUFAs）, and NoDGAT2C exhibits the strongest activity toward polyunsaturated fatty acids （PUFAs）. As NoDGAT2A, 2C, and 2D originated from the green alga, red alga, and eukaryotic host ancestral participants of secondary endosymbiosis, respectively, a mecha- nistic model of oleaginousness was unveiled, in which the indigenous and adopted NoDGAT2s formulated functional complementarity and specific transcript abundance ratio that underlie a rigid SFA：MUFA：PUFA hierarchy in triacylglycerol （TAG）. By rationally modulating the ratio of NoDGAT2A＇：2C^D transcripts, a bank of N. oceanica strains optimized for nutritional supplement or fuel production with a wide range of degree of unsaturation were created, in which proportion of SFAs, MUFAs, and PUFAs in TAG varied by 1.3-, 3.7-, and 11.2-fold, respectively. This established a novel strategy to simultaneously improve productivity and quality of oils from industrial microalgae.

摘要：The long atmospheric residence time of CO2 creates an urgent need to add atmospheric carbon drawdown to CO2 regulatory *** and systems biology(SSB),which enables manipulation of cellular phenotypes,offers a powerful approach to amplifying and adding new possibilities to current land management practices aimed at reducing atmospheric *** participants(in attendance:Christina Agapakis,George Annas,Adam Arkin,George Church,Robert Cook-Deegan,Charles DeLisi,Dan Drell,Sheldon Glashow,Steve Hamburg,Henry Jacoby,Henry Kelly,Mark Kon,Todd Kuiken,Mary Lidstrom,Mike MacCracken,June Medford,Jerry Melillo,Ron Milo,Pilar Ossorio,Ari Patrinos,Keith Paustian,Kristala Jones Prather,Kent Redford,David Resnik,John Reilly,Richard ***,Daniel Segre,Susan Solomon,Elizabeth Strychalski,Chris Voigt,Dominic Woolf,Stan Wullschleger,and Xiaohan Yang)identified a range of possibilities by which SSB might help reduce greenhouse gas concentrations and which might also contribute to environmental sustainability and *** include,among other possibilities,engineering plants to convert CO2 produced by respiration into a stable carbonate,designing plants with an increased root-to-shoot ratio,and creating plants with the ability to self-fertilize.A number of serious ecological and societal challenges must,however,be confronted and resolved before any such application can be fully assessed,realized,and deployed.