Team:UA Huntsville/Description
CosmoColi: Project Inspiration and Description
In our first year, 2019 iGEM team UA_Huntsville aims to design E. coli capable of resisting over 3000 Grays of radiation exposure! Using exogenous Tardigrade proteins Dsup and CAHS 94065, as well as genomic mutations in RecN, RecD, and RpoBC, derived from directed-evolution of E. coli, our host Organism, K12-derived E. coli will be tested to see if the exogenous proteins lend an additive effect to radiation resistance.
In the presence of non-lethal dosages of ionizing radiation, including alpha, beta, gamma, and UV radiation, genomic DNA modifications such as frameshifts and double-strand breaks occur (citation pending). Due to this, individual organisms in a bacterial population may acquire mutations which lend to increased fitness in their respective environment. Depending on environmental stressors, examples of acquired could include those lending antibiotic resistance or increased growth in microgravity conditions. In a radiation rich environment such as space, bacteria are exposed to even higher rates of radiation.
Our team hypothesizes that :
1) By transforming the strain IR9-50-1, with point mutations in RecD, RecN, and RpoBC genes(Bruckbauer et al 2019), with plasmid(s) that have separately inducible genes coding for the proteins Dsup and CAHS, all or a permutation of these proteins being expressed may lend to radiation resistance greater than that of IR9-50-1, and especially greater than WT MG1655.
2) If you can increase the resistance of organisms to ionizing radiation, you can decrease the rate of gain of function mutations that lead to antibiotic resistance. We will test this by transforming both Wild-Type and CosmoColi with a plasmid with a loss of function mutation in an antibiotic resistance gene, growing several generations of each under sub-lethal UV-light, and screening for antibiotic resistance at several intervals. Hypothetically, the WT population will gain a gain of function mutation in the antibiotic gene at a faster rate than CosmoColi.