osmotic up/down shock

Osmotic up/down shock

A summary of Allison’s data9/3/10

Upshift of Br strain

Histograms of width and length for individual time points to follow with information about

average width and number of cells

Take home: 1 hour not enough, 2 hours enough.

Br Ala-Pro steady-state

570 cells with average width 0.71 microns

Upshift for 1,2,3,4 hours

Looks like shift takes place between 1hr and 2hrs

Br upshift 1 hour

447 cells with average width 0.7 microns

Br upshift 2 hour

622 cells with average width 0.85 microns (fixed this run tonight 9/8/10)

Br upshift 3 hour

170 cells with average width 0.89 microns

Br upshift 4 hour

335 cells with average width 0.9 microns

Downshift of Br strain

Histograms of width and length for individual time points to follow

Take home: 4 hours may or may not be enough.

Br Glu-Caa steady-state

359 cells with average width 1.05 microns

Downshift for 2,4 hours

Looks like shift still taking place after 4 hours

Br downshift 2 hour

1687 cells with average width 0.94 microns

Br downshift 4 hour

1247 cells with average width 0.86 microns

Upshift of MG1655 strain

Histograms of width and length for individual time points to follow

Take home: Looks like only small increase in width after 2 hours (slower adjustment than in Br strain).

I’m going to check the analysis to make sure.

MG1655 Ala-Pro steady-state

323 cells with average width 0.68 microns

Upshift for 1,2 hours

Looks like shifting very slowly

MG1655 upshift 1 hour

605 cells with average width 0.71 microns

MG1655 upshift 2 hour

779 cells with average width 0.7 microns

Downshift of MG1655 strain

Histograms of width and length for individual time points to follow

Take home: Looks same as Br strain. Needs at least 4 hours.

MG1655 Glu-Caa steady-state

445 cells with average width 0.97 microns

Downshift for 2,4 hours

Same as Br, looks like shift is not complete after 4 hours

MG1655 downshift 2 hours

1298 cells with average width 0.8 microns

MG1655 downshift 4 hours

1106 cells with average width 0.74 microns

SummaryStrain # of cells Average width (microns)

Br Ala-Pro steady-state 570 0.71

Br upshift 1 hour 447 0.70

Br upshift 2 hours 622 0.85

Br upshift 3 hours 170 0.89

Br upshift 4 hours 335 0.90

Br Glu-Caa steady-state 359 1.05

Br downshift 2 hours 1687 0.94

Br downshift 4 hours 1247 0.86

MG1655 Ala-Pro steady-state 323 0.68

MG1655 upshift 1 hour 605 0.71

MG1655 upshift 2 hours 779 0.70

MG1655 Glu-Caa steady-state 445 0.97

MG1655 downshift 2 hours 1298 0.80

MG1655 downshift 4 hours 1106 0.74

• Colors are set to match up the same experiments between Br and MG1655 cells• Note the good agreement between the steady-state sizes of the two strains

Splitting between ceph-treated and non-treated cells…

Take home message: The widths vary systematically, although the ceph-

treated cells are systematically thinner. Incidentally, we’ve seen this

in our own experiments…

Summary (ceph/non-ceph)Strain # of cells Average width (microns)

Br upshift 1 hour (no ceph) 239 0.73+-0.05Br upshift 1 hour (ceph( 208 0.67+-0.04Br upshift 2 hours (no ceph) 552 0.85+-0.05Br upshift 2 hours (ceph) 70 0.83+-0.04Br upshift 3 hours (no ceph) 170 0.89+-0.04Br upshift 3 hours (ceph) 13 0.96+-0.1Br upshift 4 hours (no ceph) 335 0.90+-0.1Br upshift 4 hours (ceph) 0 N/ABr downshift 2 hours (no ceph) 1028 0.97+-0.05Br downshift 2 hours (ceph) 659 0.9+-0.07Br downshift 4 hours (no ceph) 1067 0.75+-0.07Br downshift 4 hours (ceph) 180 0.88+-0.09MG1655 upshift 1 hour (no ceph) 310 0.73+-0.04MG1655 upshift 1 hour (ceph) 295 0.70+-0.11MG1655 upshift 2 hours (no ceph) 489 0.69+-0.04MG1655 upshift 2 hours (ceph) 290 0.71+-0.03MG1655 downshift 2 hours (no ceph) 766 0.82+-0.07MG1655 downshift 2 hours (ceph) 532 0.78+-0.08MG1655 downshift 4 hours (no ceph) 740 0.75+-0.06MG1655 downshift 4 hours (ceph) 366 0.70+-0.10

Growth curves for upshift

Growth curves for downshift

Br upshift 1 hour

Br upshift 2 hours

3hr and 4hr time points

I didn’t add these because there are so few cells that produce good data (they

are so long that the edge parameterization doesn’t work very

well).

MG1655 upshift 1 hour

MG1655 upshift 2 hours

MG1655 downshift 2 hours

MG1655 downshift 4 hours

Contour level• Note that cell width is sensitive to contour level of

segmentation• The following slides show example galleries of images to

illustrate how the cells are segmented. If you zoom in, you can see the cell outline. I’ve tried to vary the contour level to fit each frame as much as possible.

• Note that it’s possible that the cells are in fact the same size, but that the contour levels are just different. I’m checking that out….

• Keep in mind that the cells are not drawn to scale. I’m trying to fix that but Matlab is retarded.

Br Ala-Pro steady-state

Br Ala-Pro steady-state

Br Ala-Pro steady-state

Br 2 hour upshift

Br 2 hour upshift

Br 2 hour upshift (zoom)

MG1655 2 hour upshift

MG1655 2 hour upshift

MG1655 2 hour upshift (zoom)