Project Abstract

Ionizing radiation and radiation pollution is an important environmental problem that not only affects those working around radiation facilities, but those dealing with the aftermath of widespread nuclear disasters such as those at the Fukushima Daiichi nuclear reactor or the Chernobyl reactor. Penn State’s team project will focus on using a genetic circuit introduced into E. coli bacterial cells, in order to rapidly detect and report the presence of harmful ionizing radiation. We are working to develop a robust and reliable biosensor which utilizes the lambda phage lytic-lysogenic switch coupled with a fast-acting reporter capable of producing an easily visible effect. We believe that the final construct may have the potential to rival current radiation detection methods, such as digital dosimeters.
Our hope is that the basis of our biological dosimeter system will prove to be an effective genetic system capable of detecting harmful levels of radiation and relaying it to those working in the field or affected area. We envision our system not only being useful in such applications, but also being capable of further expansion and evolution through the expanding field of synthetic biology.

Design

Our project focuses on detecting the degradation and damage of DNA associated with ionizing radiation. The initial proposed design is shown below. It consists of two parts: a sensor based on a lambda phage bistable switch, and a fast-acting reporter similar to the reporter designed by the Imperial College of London 2010 iGEM team. Additionally a modified version of the RecA protein is introduced into the system in order to provide efficient activation of the sensor circuit.

Many of the genes for detecting radiation used in this bacterial system have homologous counter-parts in Eukaryotic cells. For instance the RecA protein used in our system is part of a larger family of strand-exchange proteins involved in homologus recombination and DNA repair. Some other examples of this family include the Eukaryotic proteins Rad51 and Dcm1. For this reason it can be thought that a system similar to ours could one-day be used in self-replicating in vivo biosensors for radiation pollution bioremediation purposes and other important applications.

Click below to view more about each part of our project

Team

Ben Alouidor

Benjamin is a current senior majoring in Biotechnology that heard about iGEM during an immunology course. Currently he loves taking midday naps, and despises anything related to integrals and mathematical series.

Brian Avison

Brian is a junior majoring in Engineering Science. He learned about iGEM through his microbiology professor and thought iGEM would be a great opportunity to further his knowledge of genetics, gain valuable research experience, and explore a possible area of interest. He is a brother of Sigma Chi Fraternity and actively involved in THON and the Blue and White Society.

Alex Bina

Junior
Bioengineering

Alex wanted to join iGEM because he wanted to design and construct the genetically engineered spider that transformed Peter Parker into Spiderman. When he found out that was impossible, he used every opportunity to sabotage the Penn State iGEM team. No one has heard from Alex since August. Last we heard, he was moonlighting as State College's dark knight.

Jamie Colleta

Jamie is a junior majoring in Biological Engineering. He joined the iGEM team because of the research and learning opportunity it presented. He has always found the field of genetic engineering uniquely fascinating and loved the freedom and creativity which iGEM offered. Jamie spends his time outside of the lab as an active member of the Agricultural and Biological Engineering Society, the Atlas THON organization, Italian Student Society, and also Pizza Club

Anisha Katyal

Anisha is a senior majoring in biology. She heard about iGEM through a friend and thought it would be a great research experience. When she is not in the lab, she is actively involved in the biology club.

Elyse Merkel

Elyse is a senior majoring in Engineeing Science. She has always had an interest in genetic engineering and iGEM provided her with a unique opportunity to pursue this interest. When not in the lab, Elyse spends her time participating in all things Penn State, including Relay For Life of Penn State, THON committees, and Lion Ambassadors.

Byron Pierce

Senior
Chemical Engineering

Jim Rose

Jim is a senior majoring in biotechnology. He joined the iGEM team because it is "freaking awesome". Jim spends his time outside of iGEM...wait, time outside iGEM?

Lauren Rossi

Lauren is a senior majoring in Microbiology with a minor in Spanish and Biology and Molecular Biology. She was a participant of the Penn State iGEM team in 2010 and through this experience she developed a interest in synthetic biology. After attending the Jamboree last year, she knew she wanted to participate in iGEM again. When she is not in the lab, Lauren spends her time as a TA for a microbiology lab and is also the Vice President for the American Society for Microbiology.

Vishal Saini

Vishal is a senior double majoring in Science and Psychology with a minor in Neuroscience. He wanted the chance to get a unique research experience and thought iGEM would offer him this opportunity. Vishal spends his time outside the lab serving as the THON Chair for OPENN State and helping students as undergraduate Chemistry Tutor. He is also a Resident Advisor and an active member of the Global Medical Brigades.

Kristen Salava

Kristen is a junior majoring in bioengineering. She heard about iGEM from one of her bioengineering professors and thought it would be a great way to learn more about what synthetic biology can do. Outside of the lab, she spends most of her time with her sorority where she is the Vice President of Standards. She also is an International Envoy within the college of engineering.

Swati Prasad

Swati is a senior majoring in Marketing with honors and English with an emphasis in creative writing. She heard about iGEM from the outlaw Jimmy Rose. When she's not in the lab (Who are we kidding, she's never in the lab. She just makes the website prettier!) you can find her hoola-hooping in wal-mart.

Mike Speer

Graduate Student

Dr.Tom Richard

Advisor
Professor of Agricultural and Biological Engineering

Dr. Howard Salis

Advisor
Assistant Professor of Agricultural Engineering

Brainstorming

In the first few days of summer, we began discussing ideas for our project. Some of our first initial thoughts were to modify bacterial photosynthesis using the BCHM gene or to engineer a serotonin sensor. We thought about making a bacterial fuel cell by using Geobacter as a sacrificial anode. We also liked the idea of using bacteria to perform intelligent tasks, like mathematical arithmetic. The last idea we developed was to engineer a bacteria that would be able to detect radiation. The team spent a few days researching these topics to determine how plausible they would be and we finally unanimously agreed upon the bacterial radiation detector. With our full thoughts focused on this topic, we began looking into this idea further and discovered that the Penn State 2007 iGEM team had used the lambda phage system to also develop a bacteria that would test for radiation. However, they were not able to fully assemble their device or test it and we thought that we would be able to build upon their initial foundation.

Research

After deciding to follow up on the bacterial dosimeter idea for our project, we as a team we had to first do some research on the effects of ionizing radiation in order to better determine what exactly we would be detecting.

Currently all living organisms are exposed to a relatively low dose of radiation; this amount is so negligible that the negative effects are unnoticeable. The problem with ionizing radiation occurs when one is exposed to a high dose for a short period and/or low doses over an extended period of time. The International Commission on Radiological Protection (ICRP) recommends nuclear industry employees to limit ones yearly exposer to 50 mSv, or 100 mSv over 5 years.¹ One international study, composing 15 countries and encompassing 598,068 nuclear industry workers, found that an increased risk of cancer exists. Specifically, 99% of those tested were exposed to less than 50 mSv of radiation per year, and 1-2% of these cancer related deaths may be attributable to this exposer. It’s also estimated that 100 mSv of cumulative radiation exposer would result to a 5.9% increase chance of mortality.²


1. Cardis, E. "Risk of Cancer after Low Doses of Ionising Radiation: Retrospective Cohort Study in 15 Countries." Bmj 331.7508 (2005): 77. Print.
2. Shapiro, B. "1990 Recommendations of the International Commission on Radiological Protection." European Journal of Radiology 15.1 (1992): 93. Print.

Acknowledgments

All work and research was performed by members of the Penn State 2011 iGEM Team under the direction of Mike Speer, Tom Richard, and Howard Salis. We would like to thank the following sponsors of our team:

Affymetrix
Life Technologies
Penn State Institutes of Energy and the Environment
Huck Institutes of Life Sciences