Team:Osaka/Project/background

Background

In the modern world, radioactivity is a phenomena well understood by science, and harnessed by engineering for nuclear power generation, radiology in medicine, radioisotopic labeling in biological studies and numerous other applications. However, it is an undeniable fact that the ionizing radiation resulting from radioactive decay may cause critical effects on biological creatures, from the smallest bacteria to plants and animals including humans.

On March 11, 2011, the Great East Japan Earthquake struck off the coast of Eastern Japan and triggered a series of equipment failures, nuclear meltdowns, and releases of radioactive materials at the Fukushima 1 Nuclear Power Plant, leading to a nationwide nuclear crisis. While ‘Grays’, ‘Sieverts’, ‘exposure’, ‘equivalent dosage’ and other related terms and units became referred daily in the media, much of the general populace remained ignorant of their meanings and significance. The need for low-cost, portable and easy-to-use dosimeters was apparent as measurements of radiation exposure could only be conducted at dedicated installations spaced far apart and the numbers reported only infrequently.

Hence, this year, iGEM Osaka decided to tackle the building of a biological dosimeter. We attempted to modularly transfer radiation-response and DNA repair genes from the extremophilic bacterium Deinococcus radiodurans to the well-characterized, easily cultivable chassis of Escherichia coli. From there our efforts branched out into (1) evaluating radioresistance conferred by the heterologous genes, and (2) connecting the radiation/DNA damage response system to visible outputs such as color pigment production.