|
|
| Line 31: |
Line 31: |
| | <br><br> | | <br><br> |
| | Feel free to browse this page!<br><br> | | Feel free to browse this page!<br><br> |
| - | </p>
| |
| | <br> | | <br> |
| - |
| |
| - | == Homing Coli ==
| |
| - |
| |
| - | <i>Escherichia coli</i> is a commonly used bacterial model organism. It has lots of beneficial
| |
| - | traits, e.g. a short generation time and it can be easily manipulated. Most <i>E. coli</i>
| |
| - | strains that are used in laboratories do not exhibit high motility. The crucial element for
| |
| - | motility is the flagellum, which is rotated by a molecular motor within the cell wall.
| |
| - | Consequently, these are reduced in cultivated <i>E. coli</i> strains.<br>
| |
| - | <br>
| |
| - | Our goal is to create an <i>E. coli</i> strain with increased swimming motility on special
| |
| - | agar plates. Therefore, we will overexpress regulators and parts of the <i>E. coli</i> flagellum in cultivated strains in order to enhance bacterial swimming ability. The fastest <i>E. coli</i> strains will be selected and
| |
| - | further improved. At the same time we will then be able to create an effective motility-selection
| |
| - | method. <br>
| |
| - | <br>
| |
| - | Now, you are probably wondering what the advantage of a fast <i> E. coli</i> might be. The
| |
| - | beneficial fast phenotype can be combined with the ability of this bacterium to sense
| |
| - | specific compounds in their environments. Chemoreceptors enable it to move towards
| |
| - | or along gradients of such substances. We will use PCR-based site directed mutagenesis on the <i> E. coli</i> Tar receptor. The combination of speed and chemotaxis allows
| |
| - | us to identify <i>E. coli</i> strains, which can sense interesting compounds. Thereby, an
| |
| - | easy method for the detection of pollutants, toxins or even tumors could be provided.<br><br>
| |
| - |
| |
| - | http://www.patrickreinke.de/igem/homingcoli.jpg
| |
| - |
| |
| - | [http://jb.asm.org/content/186/22/7529.full Clive S. Barker <i> et al. </i> (2004). Increased Motility of <i> Escherichia coli </i> by Insertion Sequence Element
| |
| - | Integration into the Regulatory Region of the flhD Operon. Journal of Bacteriology, Vol. 186: 7529-7537.]
| |
| - |
| |
| - | == Synthetic Biology ==
| |
| - |
| |
| - | Synthetic biology is an interdisciplinary scientific area that has recently developed.
| |
| - | It links various fields of science like biology, chemistry, physics, molecular genetics,
| |
| - | informatics and engineering.<br>
| |
| - |
| |
| - | Due to this combination the relation of biological design and function can be investigated
| |
| - | from an entirely new perspective. The previous approach was limited to the examination of
| |
| - | a structure and its function and the attempt to explain how they correlate.
| |
| - | Recently, the reverse strategy is applied. Biological parts are specifically designed and
| |
| - | constructed according to a desired function. These parts are characterized by a standardized
| |
| - | modular design that facilitates their handling. The subsequent introduction of the synthetic
| |
| - | constructs to living cells can either cause the replacement of original cellular components
| |
| - | or result in additional elements that act cooperatively or more or less autonomously (see fig. 1).<br>
| |
| - | <br>
| |
| - |
| |
| - | http://www.patrickreinke.de/igem/synbio.jpg
| |
| - |
| |
| - | <font size="-2">After Nandagopaland and Elowitz (2011). A continuum of synthetic biology. Wild-type cells (<b>A</b>)
| |
| - | can be subject to two basic types of synthetic manipulation. (<b>B</b>) Autonomous synthetic circuits, consisting of
| |
| - | ectopic components, may be introduced into the cell. Such circuits process inputs and implement functions (red arrows)
| |
| - | seperate from the endogenous circuitry (black). However, unknown interactions with the host cell may affect their function
| |
| - | (purple arrows) (<b>C</b>)An alternative is to rewire (red lines) the endogenous circuits themselves to have new connectivity.
| |
| - | (<b>D</b>) Extending this line of synthetic manipulation, synthetic circuits could be integrated into appropriately rewired
| |
| - | endogenous circuitry to act as sensors and to implent additional functionality. Ultimate goals of this program are to be
| |
| - | able to design and construct (<b>E</b>) synthetic circuits that can functionality replace endogenous circuits or (<b>F</b>)
| |
| - | fully autonomous circuits that operate independently of the cellular mileu.
| |
| - |
| |
| - | <a href="http://www.its.caltech.edu/~haylab/research/SBReview2011.pdf">Nagarajan Nandagopal and Michael B. Elowitz. (2011). Synthetic Biology: Integrated
| |
| - | Gene Circuits. SCIENCE, Vol. 333: 1244-1248.</a> </font><br>
| |
| - | <br>
| |
| - |
| |
| - | <font size="-1">
| |
| - | Another very important and necessary feature of biological parts is orthogonality,
| |
| - | which means in this context that independent devices can be combined unrestrictedly.
| |
| - | This principle derives from the area of engineering and aims to alter subsystems,
| |
| - | without impeding others.<br>
| |
| - | <br>
| |
| - | This way cells can be modified as requested, resulting in a predictable behaviour.
| |
| - | Among others, this technique can be beneficial for the effective production of
| |
| - | certain substances, like biofuels or antibiotics.
| |
| - |
| |
| - | <br>
| |
| - | <br>
| |
| - |
| |
| | | | |
| | | | |
"
