Team:IIT Madras

Any episome (extrachromosomal genetic element) introduced into the cell shows segregational asymmetry. This is accompanied with differential growth rates in the absence and presence of episome leading to an overall loss of the episomal unit in the absence of any selective pressure. We have designed a new versatile system which can maintain any given plasmid DNA in E.coli by using user defined selection pressures, limited only by the presence of a response element to said pressure, such as most antibiotics, certain chemical and physical conditions. Depending on this selection pressure, a custom plasmid retaining system can be designed and co-transformed along with the plasmid of interest which will maintain this plasmid. A similar system can be used to “lock up” the function of a certain gene of interest, thus functioning as a combination lock, which is unlocked only when the cultures are grown in a pre-determined order of external selection pressures. In principle, using this locking system, a large number of plasmids can be maintained using a single selection pressure instead of all the selection pressures required to maintain each individual plasmid. Directed evolution, inter-species symbioses are applications that illustrate our plasmid protection system as a powerful tool for a wide range of functions.

Our Project this year, PLASMID - Plasmid Locking Assembly for Sustaining Multiple Inserted DNA is based on this concept of plamsid loss . We would be developing genetic circuits in cells to direct plasmid loss in a regulated fashion. We complement this by simple proof-of-concept experiments to check our hypothesis of directed plasmid loss in the presence of selection pressures in a pre-determined order.

This is the second time that IIT Madras has sent a team to iGEM. Our team in iGEM 08, the only team to represent India in the competition that year, secured the 'Best Foundational Advance' and the 'Best New Biobrick' prizes and a Silver, for their work on hybrid promoters which have now been added under the category of promoters (IIT Madras Stresskit promoters).

To know more about the project take a look at the PLASMID.

Our team consists of 9 Undergraduate students from IIT Madras. To know more about us, look at our Team.

Browse through our Experimental Notebook to learn about our experiments.