iGEM Triumph: Together, we stride into global TOP 10


“What is iGEM? Is it fun?”

If you ask Baidu, its answer is: international Genetically Engineered Machine competition. iGEM, which has the same age as our school SCIE, has nurtured over 4,300 synthetic biology projects and more than 20,000 genetic Parts worldwide in the past 20 years. It has also witnessed the six-year growth of the high-school team, GreatBay-SCIE.

GreatBay-SCIE members and instructor at the iGEM competition venue

But what if you ask GreatBay-SCIE?

iGEM is 19 members undergoing over eight months of ups and downs, with five months of intense work in our laboratory. It’s the moments when on the verge of desperation, running to the shaking incubators to inhale the scent of banana-flavored yeast produced; it’s burning the midnight oil twice to obtain Western Blot results then moving straight to the measurement of GC-MS. It’s tending animals more cautiously than caring ourselves, building the Shenzhen Citizen Center with LEGO blocks that comes to life more vividly than in photos. It also means 26 Human Practice activities, thrilling 12,000-word iHP documents; assembling the “Snail Hotel” in the French hotel, while awaiting approval for our mini program and anxiously waiting for responses from 11 schools or venues. It’s an immersive week-long wiki freeze battle in the lab, overnight filming, editing, and dubbing the presentation video, racing against time to perfect the project and questioning ourselves during the judging session, and finally rushing towards the Jamboree awards podium amidst the ecstatic screams and cries … 

Thus, we stumbled through, with the tiny grains of golden sand at our feet turning into starlight flying towards Paris. All fear and struggle­s were softene­d by the slightly buzzed ambience of Paris and the whispering chill of the rain. Holding onto the global gold award and Top 10 felt like a weight lifted. Winning the Best Integrated Human Practice and Best Hardware amplified our excitement, while nominations for Best Wiki and Best Presentation were the icing on the cake. Ultimately, we transformed our year-long journey, along with the lingering dissatisfaction, into the finest closing chapter of GAStroPurifier.

GreatBay-SCIE achieved the Best Integrated Human Practice Award & Best Hardware Award

And whenever mentioning the initiation of GAStroPurifier, team members always share knowing smiles. Faced with the “ecological killer” of Giant African Snails, or Achatina fulica, pervasive on the streets of Shenzhen, and the pathogenic parasite they carry, A.cantonensis, we did not choose the traditional approach of large-scale elimination. Instead, we practised a series of Experiments, Human Practices, Hardware, and Education activities. Our ALERTS (Attract – Lock – Eliminate – Reassure – Transfer – Switch) solution gradually rooted: First, we synthesized banana and papaya odors with S.cerevisiae to ATTRACT Giant African Snails, and LOCK the Snails into our hardware equipment. Next, we ELIMINATE the A.cantonensis within the snails with the toxic protein we produced; after that, the collected snails’ mucus can be extracted for detecting the A.cantonensis biomarkers to REASSURE the effects of our eliminating process manually, and if it’s successful, snails can be TRANSFER out of our hardware, with a kill SWITCH on the genetically engineered yeasts to ensure the biosafety of our design. 

Apparently, we couldn’t turn a blind eye to the fact that each Giant African Snail consumes over 500 plants, nor could we stay indifferent to the gradually chilling 31% parasitic infection rate. Perhaps, we couldn’t tip over the balance of ecological balance. Still, regarding ALERTS, GAStroPurifier, and synthetic biology, a proactive answer to the integrated control of invasive species for Shenzhen and even the world is pulsating with vitality.

Members in dialogue with the Shenzhen government and Shenzhen CDC

Once the project direction was set, the workload of our Experiments was destined to be immense, and we kept performing experiments until the last weekend before our journey to Paris. Our main targets for the ATTRACT branch were to synthesize the primary components with banana and papaya scents: isoamyl acetate and α-pinene. Using S.cerevisiae as a chassis, we conducted two rounds of genetic modification for the synthesis pathways of each substance. In this longest battlefront, nearly a month of negative results for α-pinene momentarily stalled our progress, but the intense banana scent released from the fermentation of isoamyl acetate in the first round of modification burst the entire lab with incredible joy.

Experiments in the ELIMINATE branch, working on synthesizing Cry1518-35 protein to kill A.cantonensis, were constantly shadowed by controversies and doubts. If you were to replay those 25 SDS-PAGE images frame by frame, they would narrate the story from seeking the appropriate E. coli vectors, to optimizing codons; from exploring efficient signal peptides for extracellular secretion of heterologous proteins in S.cerevisiae, to expressing Cry gene with plasmids or knocking them in the yeast genome; from the exhaustive research on the application and effects of Cry proteins, to capturing the snapshots of successful elimination of A.cantonensis under the microscope on Halloween night. But for untold one lies behind the countless all-nighters; they are filled with twists and turns but ultimately pay off.

The bench full of protein gels

To guarantee the long-term implementation of the project, we also incorporated auxotrophy and toxin-antitoxin system to design a kill switch for the genetically engineered yeasts, triggering the apoptosis of the cell death program of yeasts if the yeasts are accidentally released. Furthermore, guided by the advisor in GreatBay-SCIE 2022, we even stood on the shoulders of great minds to design five sets of synthetic arabinose promoters. Although more than 50 Petri dishes of yeast transformation piled up on the bench declared the failure of this round of promoter designs, the impressive experiences of in-depth understanding and in-person design of genetic Parts indeed polished our experience to a crystalline shimmer.

Illustration of the kill switch mechanism

Between the experiments and real-life applications, our Hardware and the Snail Locator built the sturdiest bridge. With the continuous user testing and feedback, we not only compiled each component into a readable and replicable manual, but also witnessed four comprehensive iterations of the hardware — inside the transparent acrylic boards, not only were the one-way door, automated dough compressor, and mucus collecting drawer installed, but it also preserved all those inspirations during brainstorming, the exhaustion during model drawing, the meticulousness during assembling the boards, the hysteria when the finished product was stolen, and the calmness in public demonstration.

So, can GAStroPurifier be truly good and responsible for the world? The answer emerged from our Human Practice activities, started in March. We engaged in profound two-way communications with various stakeholders, including the local governments, CDCs, residential managers, sanitation workers .etc. Exploring the contexts, defining the projects, idealizing the solutions and evaluating the outcomes, the ALERTS procedure evolved from its initial prototype form to a progressively refined state. Meanwhile, we integrated the considerations and explorations of Bioethics and Biosafety into every aspect of our project. It’s the sincere and comprehensive feedback from all stakeholders that has shaped GAStroPurifier to its current manner.

However, we firmly believe that invasive species control is not just the concern of a few; everyone can contribute to striving for the ecological balance. In our Education activities, we maintained a continuous mutual dialogue with kindergarten kids, peers, professionals, and the general public, interwoven with other sections of the project as well. Appreciate: the 24 beautifully illustrated CRISPR-based picture books, the 10-page Bioethics handbook, the 10-page biosafety proposal, the 3 modified versions of “Who is the Spy” card games, and the 18 posts with over 8,000 reads — all glowing permanently on the universe of synthetic biology.

And we, a group of crazy and passionate companions, all through moments of repeated overwhelm, persistent dedication, endless touches of laughter and tears, gained a limitless source of delight, an ever-burning sincerity, and the eternally precious GreatBay-SCIE 2023.