Overview of the Human Practice

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Youth Team, Our Future

Consisted of hundreds of teams from different countries and thousands of young students of various ages and backgrounds, iGEM provides a fantastic platform for premier undergraduates. However, biosafety issues should be paid special attention by these enthusiastic scientific beginners. In this part, we would like to introduce our special concerns on safety issues, especially on prevention of horizontal gene transfer, and ideas for future iGEM competitions with more securities.

Our project in this year focuses on developing a heavy metal decontamination plasmid kit. Many heavy metals were involved in the process of experiments, and we need to design and synthesized some vital genes (PbrR-MBP for example) to play roles in bio-absorbance. Realizing that special attention should to be paid to bio-security issues when doing these bench works, we had cautious considerations and careful designs as followings:

First of all, a laboratory regulation has been made by team members according to national rules and requirements from supervisors. As a result, we have strict guidelines and well-protection when doing experiments related with heavy metal such as mercury and lead. Team members would always guarantee effective cleaning work when the experiments were finished, and decontamination facilities were also well-prepared for the potential pollutant. Secondly, we designed the kit to preserve bacterium in special condition, which would satisfy requirements for decreasing probabilities of environmental contamination and gene transfer. Moreover, the auto-aggregation module has crucial functions to solve safety issues. By precipitating and localizing the bacterium carrying with metals, this design not only helps us gather toxic metals more efficiently, but also reduce the chance of gene transfer to the highest extent during the field application. These efforts are proof-of-concepts to successfully ensure bio-safety of our project.

The goal of ensuring biosafety and eliminating deleterious gene transfer, however, cannot be achieved by efforts of only a few teams. Collective intelligence significantly matters. Risk assessment of projects should be carefully conducted. Information and experience sharing among teams is important. New ideas for a safer iGEM competition should be encouraged. They are also what we exactly did in this year.

Particularly, we’ve proposed some solutions of HGT, hoping to be useful for future iGEM competitions and making parts, devices and systems more desirable and safer. Nowadays, many measures are taken to minimize the adverse effects of horizontal gene transfer. [BOX 1] However, they’re not practical for further application and cannot avoid the release of Gene Modification Organisms into environment. Here, we propose that some modules could be delicately designed in order to eliminate HGT, and hoping that these ideas will be verified and applied by iGEM teams in the future.

The first idea is to utilize gene deletion techniques, which often depend on availability of suicide vectors. [3] The plasmid containing the target gene can only grow in strains, which, for instance, have a certain gene encoding proteins necessary for plasmid replication. [4] The suicide vector can only survive in the host strain thus avoid gene transfer. The second idea is to combine target gene and special gene together in order to construct an element, which could destroy new host cell once transfer occurs. We could construct a plasmid where transformation would activate expression of restriction endonucleases aiming at self restriction sites. Similarly, we could put the target gene with a virulent gene (ccdB for example) together into a certain transposon, which belongs to host bacteria expressing repressors to inhibit that virulent gene. Once gene transfer happens, the transposon would come into a new host cell which has no repressor gene, and lead to host cell lyses and thus the prevention of target gene transfer. [Figure 1]

Our team also made the collaboration with Paris team. Chinese Version download: PDF More details could be in on the page of Collaboration.（ learn more）

Last but not least, iGEM exerts increasingly influence on many aspects, from student individuals to scientific institutions, from local bio-safety agency to even departments of science and technology in governments. Therefore we have a perspective on how to develop a more influential and safer iGEM competition.[5] [Figure 2] We believe that contributions to safer and better synthetic biology would depend on supervision, good scientific environment and our own responsibilities.

References

[1] Florence Faureza, Daniel Dory, Vincent Le Moignea, Rodolphe Gravier, and André Jestin. Biosafety of DNA vaccines: New generation of DNA vectors and current knowledge on the fate of plasmids after injection. Vaccine Volume 28, Issue 23, 21 May 2010

[2] E. K. Weibel and B. D. Seiffert. Biosafety investigations in an r-DNA production plant. Applied microbiology and biotechnology Volume 39, Number 2

[3] Silva Ode S, Blokesch M. Genetic manipulation of Vibrio cholerae by combining natural transformation with FLP recombination. Plasmid. 2010 Nov;64(3):186-95. Epub 2010 Aug 13.

[4] Resources - University of Maryland School of Medicine

[5] DNA synthesis and biological security NATURE BIOTECHNOLOGY VOLUME 25 NUMBER 6 JUNE 2007