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Team:BYUProvo/Project
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Revision as of 16:06, 13 September 2012
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| Home | Team | Team Profile | Project | Parts | Modeling |
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Safety | Outreach | Collaboration | Attributions |
Contents |
Overall project-Detect and Destroy!!!
Bio Busters
Cholera is an acute disease caused by the ingestion of Vibrio cholerae through contaminated food and water. Because cholera is most common in developing countries that lack proper water treatment facilities and education for simple water purification techniques, it has remained a prevalent worldwide health issue. Our goal is to find biological parts and design a circuit in E. coli that would enable it to hunt and eliminate V. cholerae from aquatic environments. This circuit consists of E. coli detecting V. cholerae biofilms, swimming towards and degrading them, and eliminating the V. cholerae bacteria. We found a quorum sensing system in V. cholerae that could be expressed in our E. coli chassis, enabling it to detect the presence of V. cholerae in its surroundings. This sensing system will then be incorporated into E. coli’s chemotaxis system so that it swims towards V. cholerae once the quorum sensing receptors detect its presence. We found multiple genes which could break down the V. cholerae biofilms. Among these are savinase, amylase, and CytR (I would list them all). In addition, we have found a toxin from the T4 phage, called holin, which should kill the the Cholera. In summary, we have been able to locate biological parts that appear capable of endowing E. coli with the abilities to recognize the presence of V. cholera biofilms, change its flagellar movement to swim towards them, degrade their biofilms and then kill the V. cholerae bacteria. We are currently testing these quorum sensing and biofilm destroying genes to determine if the proposed circuit will function as hypothesized.
E. Colonoscopy
Colon cancer is the third leading cause of cancer death in the US. Colon cancer exhibits aggressive metastasis; as a result, early detection and treatment are necessary for successful treatment. Compared to normal cells, colon cancer cells give off excess heat, reactive oxygen species (ROS), and lactate. Last year, BYU IGEM demonstrated that heat and ROS can be detected by genetically engineered E. coli. Thermosensitivity was achieved by manipulating a temperature dependent RNA hairpin loop derived from Listeria to melt within a difference of two degrees. This year we plan to develop thermosensors that can identify a narrower temperature range, especially temperatures around physiological average. We will do this by random mutation of our current thermosensors, as well as using mathematical modelling to predict how altering the DNA sequence will change the melting temperature. Also, we are currently developing DNA toe-holds which we hope will narrow the melting range even further. To our knowledge, this process has never been tested before. The lactate sensor will be achieved by mutating periplasmic Glucose Binding Protein (GBP) to bind lactate. Upon binding of lactate, a cascade will result, activating the OmpC promoter and producing GFP. Through the amount of GFP produced, we can use statistical analysis to calculate the concentration of lactate in colon cancer cells. We plan to incorporate the heat, ROS and lactate sensors into a molecular AND gate which would create a reporter only if all three elements are present. By addition of a Cre-Lox system, we will ensure that reporter continues to be produced once the AND gate is activated. In theory, this process will be able to accurately and specifically detect colon cancer cells.
