As a famous saying goes, "Quantitative changes lead to qualitative changes". This year team XMU-China did experience a period of pain. During the brainstorming stage, our team was divided into 5 groups to explore different project directions for the 2019 iGEM competition. We initially constructed 5 alternative projects in 8 weeks:

1. Reuse of Waste Edible Oil: Efficiently Producing Surfactants in Bacillus Subtilis

2. Plasmid Delivery System Suppresses the Release of Inflammatory Cytokines in Inflammatory Bowel Disease (IBD) to Relieve Symptoms

3. Using Alkaloids to Kill Fouling Organism Barnacles

4. Repairing Wooden Buildings with E. coli Secreted Cellulose

5. Using Bacteria to Simulate Social Relationships

With these preliminary projects, we joined this year's Southern China Regional Meeting, and this meeting did help us determine our project's direction. During the brainstorming stage of our team, there was an idea that was promoting at that time: Using Alkaloids to Kill Fouling Organism Barnacles as mentioned above. This was surprisingly similar to the design introduced by Greatbay_SCIE in the meeting presentation. We had more in-depth communication with Greatbay_SCIE team for genetic circuit. As we hope to construct innovative project, this stimulated us to explore more new fields through brainstorming. The meeting was a great impetus for us to turn our attention to the study of sociology using synthetic biology.

Then we did a pointed literature search and summarized some ideas that could support this project.

Using microbes for sociology often gains interesting results. Japanese scientist Nakagaki (1) used slime molds to crack a maze successfully in 2004. In 2010, Tero (2) just spent 26 hours by using slime molds and sweet oat granules simulating the road map of Japanese Shinkansen which actually spent several decades to build. People wondered why slime molds without nervous systems can solve such complicated network problem in such a short time, but no wan can give a convincing answer so far. Shapiro (3) pointed out in 2007 that bacteria have cognitive, computational and evolutionary abilities. Meanwhile, they can utilize complex intercellular communication mechanisms to control the basic cellular biology functions of "advanced" plants and animals, which means that it is possible to use bacteria to simulate some basic social forms or interactions.

Bourke, an evolutionary biologist, gives an explanation for the biological evolution to social evolution. He believes that: genes form genomes, prokaryotic cells and protobacteria form eukaryote cells, eukaryote cells form multicelled organisms and multicelled organisms form eusocial societies or join with other organisms to form mutualisms. (4)

In fact, observing the evolution of a stable species to another stable species can better help us understand the social structure. However, due to the consideration of time cost, it seems to be a more viable way by using synthetic biological method to create engineering bacteria with different functions that we need directly.

So, we abstracted social relationships into Mutual Benefit, Altruism, Spite and Selfishness. Our team prepared to build genetic circuits around these 4 relationships.

But it was the origin version of our project, we lately improved our project for more than 4 times and finally formed the final version Re_Gone with the wind. You can see more details about why and how we updated the project version at the page of Integrated Human Practices.

Reference

1. T. Nakagaki, et al., Yamada, Maze-solving by an amoeboid organism. Nature 407, 470 (2000).

2. A. Tero, et al., Rules for Biologically Inspired Adaptive Network Design. Science 327, 439-442 (2010).

3. J. A. Shapiro, Bacteria are small but not stupid: cognition, natural genetic engineering and socio-bacteriology. Stud Hist Phil Biol & Biomed Sci 38, 807-819 (2007).

4. C. E. Mouden, Life: social to its core Principles of Social Evolution. Evolution and Human Behavior 33, 79-80 (2012).

"After all, tomorrow is another day."

The far-reaching novel "Gone with the Wind" depicts the progress of change about a couple from loving each other to hurting each other, As the character in the novel stands for a certain group in literary form rather than a single invidual. We hope to interpret the relationships between groups through bacteria this year.

From marriage to opposing, "cooperative" genes and "aggressive" genes were applied to interprete in bacteria aspect.

The "cooperative" gene were split and respectively transformed into two groups of bacteria so as to help these bacteria survive better under the tough situation.

At the same time, the two groups of bacteria carry different "aggressive" genes, who would start hurting each other (expressing proteins) due to the fuses (inducers).