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Westphal V, Rizzoli SO, Lauterbach MA, Kamin D, Jahn R, Hell SW (2008) Video-rate far-
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36
Figure legends
898
Figure 1: Comparison of SIM, WF and CLSM in resolving fine details of cortical microtubule
899
organization in hypocotyl epidermal cells of
Arabidopsis thaliana expressing either GFP-MBD
900
or GFP-TUA6 microtubule markers.
(A) Overview of bundled GFP-MBD-labeled microtubules
901
in a hypocotyl epidermal cell of wild type Arabidopsis thaliana (see also Fig. S1A).
The boxed
902
area includes a loop within a bundle which is readily visible by SIM (top inset, arrow), but not by
903
WF (middle inset, arrow; Fig. S1B) or CLSM (bottom inset, arrow; Fig. S1C).
(B) Overview and
904
detail of a cortical microtubule bundle in an epidermal cell expressing TUA6-GFP (Fig. S1D).
905
Top inset shows the discontinuous incorporation of the tagged tubulin revealed by SIM which is
906
however not discernible by WF (bottom inset; see also Fig. S2A to S2C).
(C) Overview and
907
details of microtubule branch formation and release in a hypocotyl epidermal cell expressing
908
GFP-MBD microtubule marker (Fig. S1F) acquired with a 63
×1.40NA oil immersion objective.
909
A nascent branch (top inset, arrow) and a newly released branch (top inset, arrowhead) are
910
clearly visible by SIM, but not by WF (bottom inset, respective arrow and arrowhead). (D)
911
Microtubule bundle complexity in a hypocotyl epidermal cell of the mpk4 mutant as visualized
912
by SIM (Fig. S1J). Such bundles (white boxed area in D) can be resolved in detail by SIM (top
913
inset) but not by WF (middle inset) or CLSM (bottom inset). (E to G) Details (left column) and
914
orthogonal projection (right column) of three closely proximal microtubules (lines in E to G)
915
from the dotted boxed area in (D). By SIM (E; Fig. S1J) the three microtubules are clearly
916
separated as three fluorescent spots, while in the respective WF (F; Fig. S1K) and CLSM (G;
917
Fig. S1L) images the three microtubules appear as a fuzzy fluorescent area. (H to K)
918
Quantitative analysis of the resolution of individual GFP-MBD (H, J) or GFP-TUA6 (I, K)
919
labeled microtubules by means of SIM and WF (H, I) or CLSM (J, K). The graphs represent
920
averaged, co-aligned and normalized intensity profiles (as described in Materials and Methods
921
section) of individual cortical microtubules (n= 27 and 42 for SIM (GFP-MBD and GFP-TUA6
922
respectively), 27 and 42 for WF (GFP-MBD and GFP-TUA6 respectively) and 27 and 47 for
923
CLSM (GFP-MBD and GFP-TUA6 respectively)). Scale bars: 5
μm (A to G), 2 μm (insets of A
924
to C).
925
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37
Figure 2: Quantitative analysis of GFP-MBD-labeled cortical microtubule bundles by means of
926
absolute fluorescence intensity comparing the resolution capacity of SIM, WF and CLSM. (A to
927
C) SIM overview (A; Fig. S4A) of an area with microtubule bundles with different microtubule
928
numbers (1, blue line; 2, green line; 3, red line and 4, purple line) quantified by means of
929
fluorescence intensity profiling (B) corresponding to the colored lines in (A) and quantitative
930
evaluation of microtubule number per bundle (C; mean
±SD; R
2
, linear correlation coefficient; *,
931
p<0.001; n=119, 99, 33, and 26 measurements for one, two, three, and four microtubules,
932
respectively). (D to F) The same area shown in (A) after WF acquisition (D; Fig. S4B) with the
933
representative (E) and the averaged maximum fluorescence intensities intensities (F; mean
±SD;
934
R
2
, linear correlation coefficient; *, p<0.001 comparing 1 with 2 and 2 with 3 microtubules; N.S.
935
non-significant difference (p=0,158 between 3 and 4 microtubules); n=119, 99, 33, and 26
936
measurements for one, two, three, and four microtubules, respectively). (G to I) CLSM imaging
937
(G; Fig. S4C) of the same area depicted in (A) showing the representative (H) and the averaged
938
(I; mean
±SD; R
2
, linear correlation coefficient; *, p<0.001 comparing 1 with 2 microtubules;
939
N.S. non-significant difference (p=0,057 between 2 and 3 microtubules and 0.051 between 3 and
940
4 microtubules); n=119, 99, 33, and 26 measurements for one, two, three, and four microtubules,
941
respectively) fluorescence intensities corresponding to increasing microtubule numbers per
942
bundle. (J to L) Detailed view (J) of the boxed area in (A) and the fluctuation of absolute
943
fluorescence intensities along the longitudinal profile (represented by red, tan and orange
944
brackets in J; white arrow points to fluorescence intensity depression between red and tan
945
brackets) by SIM, WF (K) and CLSM (L). Brackets in (K, L) correspond to the fluorescence of
946
the respective brackets in (J). Note that the intensity along the red and the tan bracket is well
947
discriminated in SIM, declining incrementally (K), less discriminated in WF declining nearly
948
linearly (K) and not discriminated at all in CLSM (L). Black arrows in (K, L) correspond to the
949
intensity drop marked with white arrow in (J). Scale bars: 5
μm (A, D, G) and 2.5 μm (J). For
950
clarity the colored line bars in A, D, G, corresponding to the fluorescence intensity profiles
951
plotted in B, E, H are twice as long as the actual profile length.
952
953
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