Difference between revisions of "Part:BBa K343007"

Revision as of 16:53, 22 October 2010

Photosensor generator

Results

Bacteria containing this part will exhibit a lowered tumbling rate when exposed to blue light (wavelengths around 350nm - 450nm). This was analysed with the help of video microscopy and the open source software [http://db.cse.ohio-state.edu/CellTrack/ "CellTrack"]. The individual cells trajectory was tracked and their speed measured. The tracking results are as follows:

From left to right, trajectory of: E.Coli with photosensor exposed to blue light, E.Coli with photosensor exposed to red light and E.Coli Mg1655 Wildtype exposed to blue light: (Blue dots show the location of the cell in the given frame, so the number of dots equals the number of frames from the sample.)

The phototaxic bacteria move more in a straight line when exposed to bluelight, as can be seen when comparing the trajectories of the thee bacteria given earlier. These were taken from a batch of 10 cells tracked per sample.

Sequence and Features

Assembly Compatibility:

10
COMPATIBLE WITH RFC[10]
12
INCOMPATIBLE WITH RFC[12]
Illegal NotI site found at 1863
21
COMPATIBLE WITH RFC[21]
23
COMPATIBLE WITH RFC[23]
25
INCOMPATIBLE WITH RFC[25]
Illegal NgoMIV site found at 153
Illegal NgoMIV site found at 411
Illegal AgeI site found at 1665
1000
INCOMPATIBLE WITH RFC[1000]
Illegal BsaI.rc site found at 1107
Illegal BsaI.rc site found at 1380
Illegal SapI site found at 881
Illegal SapI.rc site found at 1881

@@ Line 1: / Line 1: @@
 __NOTOC__
 <partinfo>BBa_K343007 short</partinfo>
-Molecular mechanism of the photosensor
+===Results===
-The fusion,chimera-protein coupled to the chemotaxis pathway. Figure taken from Trivedi et al.(2)
+Bacteria containing this part will exhibit a lowered tumbling rate when exposed to blue light (wavelengths around 350nm - 450nm). This was analysed with the help of video microscopy and the open source software [http://db.cse.ohio-state.edu/CellTrack/ "CellTrack"]. The individual cells trajectory was tracked and their speed measured. The tracking results are as follows:
-The fusion,chimera-protein coupled to the chemotaxis pathway. Figure taken from Trivedi et al.(2)
-The photosensor acts directly on the tumbling frequency by effecting E. Coli's normal chemotaxis pathway. When exposed to bluelight, the sensory rhodopsin II will absorb the photons and undergo a change in ultrastructure, which is being transduced through HtrII on to the Tar domain. This effects decreases the autophosphorylation of the CheA protein, which in turn again decreases the amount of phosphorylated CheY, which just means that less of it will get phosphorylated. If there is less of the CheY-P, then there is a smaller chance of one of these molecules binding to the flagellar motor and making it turn clockwise, thereby inducing a lowered tumbling frequency in the system. The photosensor can also act in the opposite way, inducing a higher tumbling rate in the bacteria. Which effect the sensor will have depends on where NpHtrII and StTar are fused in the HAMP domain. If the fusion contains 20 more basepair of the HtrII domain and 20 less of the Tar domain, the photosensor would have the opposite effect and would be increasing the autophosphorylation of CheA. Usage and parameters
-The part requires retinal to work in E.Coli. This can be achieved through adding retinal to the liquid growth medium and/or the plates. Currently we are doing experiments on wether the part also functions with an internal retinal source, ie retinal synthesis in E. Coli. On top of adding retinal the cells will have to be grown in the dark for at least two hours after the addition of retinal to the growth medium if you want to see an effect. This is so that the photosensor is not exposed to light before the experiments and will result in maximum output if exposed to blue light. Results
+''From left to right, trajectory of: E.Coli with photosensor exposed to blue light, E.Coli with photosensor exposed to red light and E.Coli Mg1655 Wildtype exposed to blue light: (Blue dots show the location of the cell in the given frame, so the number of dots equals the number of frames from the sample.)''<br>
+[[Image:Team-SDU-Denmark-PSblue1.png | 150px]]
-Bacteria containing this part will exhibit a lowered tumbling rate when exposed to blue light (wavelengths around 350nm - 450nm). This was analysed with the help of video microscopy and the open source software "CellTrack". The individual cells trajectory was tracked and their speed measured. The tracking results are as follows:
+[[Image:PSred sample 1 trajectory - Cell 1.png | 150px]]
+[[Image:Team-SDU-Denmark-WTblue1.png | 150px]]
-From left to right, trajectory of: E.Coli with photosensor exposed to blue light, E.Coli with photosensor exposed to red light and E.Coli Mg1655 Wildtype exposed to blue light: (Blue dots show the location of the cell in the given frame, so the number of dots equals the number of frames from the sample.)
 The phototaxic bacteria move more in a straight line when exposed to bluelight, as can be seen when comparing the trajectories of the thee bacteria given earlier. These were taken from a batch of 10 cells tracked per sample.